NUT — 4. L.A ON-f- ———_—_—=—_—_=_—— ee ae eae RELATION BETWEEN Woop STRUCTURE AND PENETRATION THESIS FOR DEGREE OF M. S. PAUL CLIFFORD KITCHIN hoe ws . Sengeseeneingorenatnceeennnnnsnereneresrreeereteereree eee . nd THES ge f~~.. TRE R&LATION RETHEEN THE STRUCTURES OF SOWkK CONIFEROUS WOODS AND THEIR PENETRATION BY PRESERVATIVES, Thesis for the Degree of Master of Science. Paul Clifford Kitchin 1917, THESIS THE RELATION PETHEEN THE STRUCTURES OF SOWR CONIF@ROUS WOODS AND THEIR PENETRATION BY FRESERVATIVES. The incentive for the work which I have attempted on the relation, if there be any, between the microscopic structures of some of the soft woods ana the degree to which they are penetrated by creosote oil, was furnished by one of the conclusions reached by Teesdale (1) in his work on that subject. The conclusion was as follows, "The results obtained with a given species of wood cannotabe ap- plied to another species,however similar in structure the two may be. This fact is strikingly evident in the treatment of heartwood larch" (Larix occiaentalis)"and tamarack"(L. lartcina). Teesdale treated three pieces of each species under identical cond it fons and reported the re- sults as follows; L. occidentalis. Average longitudinal penetration 3.17 ins. Average radial penetration 0.09 ins. EL. laricina. 4.verage longitudinal penetration O.og ins. Average radial penetration 0.04 ins. Penhallow (2) describes these two species as follows; Larix occidentalis Nutt. "PRANSVERSE. Growth rings usually breaa, the dense and prominent Summer wood about one half the spriné wood, from which the transition ts abrupt. fTracheids of the summer wood large, syuarish, in regular rows. Tracheids of the spring wood very large and thin walled, squarish hexag- onal, in very regular rews, rather uniform. SHedullary rays prominent, rather resinous and broad, one cell wide, distant 2-6 rows of tracheids. Resin passages few, large, without thyloses, the epithelium narrow, rather thin walled, the nutritive laye@ thick walled and resinous. Resin celis 1019905 wieely scatterea on the outer surface of the summer woea, but readily recognised by their abunaant resinous contents. RADIAL. Fays conspteueusly resinous thruout; the tracheias narrow and woréinal, rarely interspersean. fay cells chiefly straight theuout and equal to 3-8 spring trachetas; the upper ana lower walls chiefly thick and unequal, sparingly pitted thruout, more strongly sa in the summer woaa; the terminal walls coarsely pitted thrugut; the lateral walls with elliptical ano aistinetly boraerea pits, with @ narrou;, chiefiy ebiong or lenticuier orifice, numeraus, at first 6-& per tracheia, secon greatly reauceda in size, and in the summer weod abruptly 1 per tracheia. koraerea pits conspicuausly in 1-8 raws, more rarely in one row anly, ellinvtical, the orifice very laree. Fits an the tangential walis ef the sunner wooa rather numerous but amall ana often obscure. Resin cells about 14.5 microns wiae and 60 ~150 microns lang. TANGENFIAL. hays rather numerous, low to very hieh. Fusiform rays with a lLarée resin canal without thyloses, the exithelium ealls thick walleas Ordinary rays often very high, chiefly very uniform, ana not contracted at the position af the rarely interspersea tracheias, the parenchyma cetis rather unequal, sometines in pairs, oval ar obions, somewhat variable. Larix americana Michx. (tl. laricina (Luroi) kach).. TRUNSVERSE, Grawth rings rather broad ana uniforn, sonetines aouble.. Summer waoda rather dense, about one fourth to one half the epriné wood, from shich the transition is either graaual ar abrupt; the tracheids small, conspicuously unequal, ana not in very reéulor rows, distinctly rounded. Spriné tracheias large, hexatonal, raaially elandated, thin. heaullary rays prominent, broaa, one cell wiae, aise tant 2-8, rarely more, tracheias. fResinous passaéses large, equal to 2-3 tracheids, aevoid of thyloses, the epithelium cells fiat, rather thin wallea, the nutritive parenchyma scanty, thick walled; not very numerous, chtefly in the summer wood. Resin celts few, widely scattered on the outer face of the summer woad, non resinous, distinguished by (1) their thin outer walls and advanced position, and (2) by the sieve plate structure of the terminal walls. RADIAL. Rays somewhat resinous thruout, the trachetas proninent, numer= ous and marginal. Parenchyma cells straight or barely contracted in tke summer woad, the upper and loser walls thick, unequal, and usually sparingly pitted; the terminal walls coarsely pitted thruout; the iateral walts wtth distinctly bordered pits, tke narrow orifice chiefly oblong, 2-6 per tracheid,. becoming distinctly smaller twarda the summer woed, where they are abruptly reduced to 2 and finally Z ner tracheid. Por- aered pits in 1 or 2 rows, laré¢e, elliptical, becoming smaller and round tward the summer wood. Pits often showing an equatorial banda.. Pits on the tangential walls of the sumner wood numerous, small, approx= imate, on the outermost tracheids only. The outer summer tracheids often show a marked tendency tward the formatton of spirals. Resin celis 15 microns wide, about 125 microns long. TANGENTIAL. Rays numerous, medium to high, sparingly resinous. The fusiform rays with a broad central tract and a large resin camal with- out thyloses. fhe ordinary rays rather broad, sometimes 2 seriate in part, the resin cells thick walled, chiefly rather equal, uniform,obloné¢, more rarely oval. Rays somewhat contracted at the position of tke nar- row and interspersed tracheids." A careful comparison of the foregainé descrirtions shows that in thc transverse szcttons the tracheids of the summer wood are larger in Larix occidentalis than they are in Larix laricina. It has been found to be a fact in wood preservation that the dense summer wood of some species, notably of the hard pines, is much more eastly penetrated, and absorbes more creosote than doeg the more open spring wood. The presumea cause for this difference is thr presznce of resin passages in the summer wood, however. ¢iven resin passages in the summer wood of both Ll. laricina and L.occidentalis, the larger tracheias in the latter may be a contributing factor in it's eaz:ier penetration. The radial and tangential sections, according to the descriptions, show no appreciable differences,. at least no differences whitch would be active in assisting or retarding the penetration of preservatives. Ag the wood of conifers is made up almost wholly of tracheias, some of these at least , are analagous to the tracheary system of the 4Anéiospermous woods. The question of the penetration of preservatives into wooa resolves itself into two problems; first, the structure of the conducting system of the wood, and secand,. the penetrability of the cell walls. Roth Ratley (3) and feesdale (4) have shown that the passage of creosote otl thru the cell wall is practically nesli¢gible. Therefoee rm’ remaing to be nade a detailed stuay of the individual tracheias of L. laricina and L. occidentalis with reference to their role as con- ducting structures. This,then,is the point fron which the problem has been attackt,and though I consiaer tit by no means solved, as. that would take much more time than was available, the results give an indiczition as to what the structural differences may be which cause this seeming paradox in penetretion . fhe Methad of Investié¢gation.. Typical specimens of Larix larictna and L. occiaentalis were se- curea thru the kindness of Wr. 4.D. Tiemann of the Forest Products Laboratory at Madison, Wisconsin. That of L. laricina was a ptece from the collection of "Commercial Woods of the Unitea States” pre- pared by the Forest Service,. while that of tae L. occidentalis cane from the collection at the Laboratory @t Madison. Small pieces of each wood, about the thickness of a toothpick and 3/4" to 1" long were split from the specimens and macerated by Schultzes methoa*. However instead of using all nitric acid as Schuttze did, I used about 1/4 water, applying more heat and lengthening the time of maceration, thus being able to control the process to a ¢reater extent than with strong acid. After maceration the tracheids were boiled in water for a short time to exzpell the acid and air. The macerated material was then placed in auvial and used as needed. Small amounts of the wood from the vial were carefully separated into individual cells with two needles and using a dissecting lens. Only one tracheid was mounted on the slide at a time and was placed in just enough vater to hold the cover ¢lass down. The water gradually evarorated and it was found that the parts of the indiviaual pite were easiest to see at the time when the water was leaving them. All measurements of tracheid lengths were made in spaces of the ocular micrometer using the 16 mm objective. Such a space on the micro= scope employed was equal to 0.00845 millimeters. The remaining meas- urements wer2c all made in spaces of the ocular micrometer using the 4mm. objective. Such a space on the microscope used was equivalent to 0.00191 mm At the concluston of each set of measurements the average was secured and translated inta terms of millimeters. From these measure= *ChamberlIain, C.J. Methods in Plant Histology, P. 109, 6 ments there were calculated the fallowing; (1) The penetrable bordered pit area. According ta Bailey (3) the bordered pits are the means of pas- sage for liquids sgainég from one tracheid to another. Wot all of the boyaered pit,however, is available for this purpose. The accompanying diagram shows the various parts of the bordered pit bath entire ana in s2ection. 7s} Oe A, surface view of bordered pit. F and C, sectionat views of boredred pits. Fr, embossed or boraereda area of sziconaary wall. Oe, pit or orifice (mouth) tn the secondary wall. Me,. membrane. Ts, thickened area of membrane, or torus.. (After Railey). According to Pailey(3) the only part of the boraereda pit structure which functtons in the transmission of preservatives is the pit membrane, les5 the torus which ts locatea in the center of the same. After wood is seasoned, this membrane, from the torus to the edge, is composed of a number of radiating ribbons so shrunken that there is actual space between them. This area of radiating ribbons is what I have aesignated as "the penetrable bordered pit area”.. In oraer to compare the the penetrable bordered pit area of ane wood with that of another it ts not enough to determine the spenetra- ble bardered pit area af an average tracheid af each. To make this compartson the len¢th of an average tracheid,.in millinetors, was ai- vided into the averatge number of bordered pits per tracheid ana the penetrable bordered pit area of an average pit was then multiplied by the quotient obtained. fhe result was. ‘the penetrable bordered pit area per millimeter of tracheid length. This wags then direetly comparable to the same length of tracheid in any other species. (2) The simple pit area. Here the average area ofa simple pit was aeterminea, and then mul- tiplied by the average number of simple pits ina tracheid. Then,by the same method age described for the penetrable bordered pit area, the simple pit area per millimeter of tracheia lensth'was aocertained. Zhe preliminary tables of measurements on Larix laricina ana Ll. occ- cidentalis are as follows; (See next page). & TARLE I. Larix laricina(heartwood) Forest Service spécimen. 1 2 3 a 5 6 7 § 9 10 aD. mM. Length 500 890 500 455 510 56590 440 485 440 440 470 8.97150 Diameter 43 82 40 46 35 40 40 40 42 38 40 0.07640 No. bord. pits. 185 188 Ww 27 #195 200 158 216 206 i128 166 187 Pit diam. 12 12 12 12 12 Le 1% 12 12 12 12 0.02292 Torus dian.8& 8 8 8 8 8 8 8 8 8 8 0.08528 Mouth diam.4 4 4 4 4 4 4 4 4 4 4 0.00764 No, simple pits. 325 3380 269 197 225 281 246 250 288 234 264 Ave simple pit area. 2 2 2 2 2 < 2 2 2 2 2 0.000007 No.reys orossed. 8 8 8 5 7 10 6 4 7 "7 7 The penetrable borderea pit area is; Av. area of 1 pit 0.00035 8q. mm. Av.. area of torus 0.00019 Penetrable area of 1 au. pit 0.00019 sq. mn. Av. no. pits per tracheia _____. 187 Penetrable area of 1 av. tracheta 0.03553 sq. mm, The simple pit area is; Av. area of 1 pit 0.000007 sq. mm. Av. na. pits per tracheia 264 Simple ptt area per av. tracheid 0.001848 SQ. MMe The peneteable bordered pit area per mm. of tracheid is 0.00512 sq.mm The simple pit area for the same unit is 0.000462 sq. mm. § Tibbs II. Larix Length 650 510 530 620 Diameter 35 30 40 40 No. bord. pits. 215 260 260 288 Pit dian. 13 13 13 13 Torus dian.7 7 ” 7 Mouth G@iam.5 5 5 5 No. simple pits. 268 202 806 880 Av. sinuple pit ares. 2 8 8 1 No. rays orosséd. 11 8 10 13 The penetrable borderea Av. area of 1 pit Av. area of torus Penetrable area of 1 au. pit Av. now. pits per tracheiad Penetravle area of JI av. The simple pit area is; Av.. area of 1 pit Av, no. pits per tracheia Simple pit area per au. occidentalis(heartwooa) tracheia tracheiad 5 6 7 510 450 620 46 40 45 220 220 250 13 13 13. 7 ? 7 9) 5 5 171 149 326 1 2 3 3 6 10 pit area is; 0.00048 sq. 0.00034 sq. 620 40 23 3 19 82i 12. Old ~----248 0.08527 sq. 600 40 250 18 546 MMe MMe mM 10 600 40 300 18 540 13 0.000007 Sq. mm. o25 The penetrable bordered pit area per mn, 0.01804 Sqe mm. 0.002871 sSqe mm. Forest Service specimen. Qu. 561 40 248 13 325 10 mm. 4.74045 0.07640 0.024883 0.013887 0.00955 0.000007 of tracheia len¢th is The simple pit area for thes same unit is 0,000490 sq. mm.. 10 4. comparison of the figures given in Tables I ana II shows that the simple pit area is not directly connected with the penetrance figures as given by Teesdale (1). However the penetrable bordered pit areas show enough of a correlation to the figures of Teesdale to warrant a more critical study of a large number of bordered pits in order to ryrther test and vertfy the results of the preliminary survey. There- fore I abandoned any clase study of the simple pit areas and concen=- trated on measurements of the penetrable areas of bordered pits. The rest of the measurements, on the fresh material, were taken merelyt o check the first ones and establish their accuracy as far a&% possible. Table III shows the measurements of 100 bordered pits, selected from 10 averaée tracheids,. 10 pits per tracheid, of Larix laricina. The avereges of each 10 pits are incorporated in Table IV under the headings of Fit diameter; Torus atiameter, and Mouth diameter. Tables V and VI show the correspondiné measurements for Larix occidentalis. (See following pages for tables) il TARLE IIl. ¥easurements of 100 bordered pits penetrance specimen of Larix laricina, from Michi¢an.. Diameters Diameters Torus Mouth Av. of 1¢, Fit Mouth Av. of 10 Forus Pit OOO9N9EOO0SOQ ee eee © Ge @ @ RADIAL OSLO WOO WOW DHOWIO'N&S HMODOSMNADANO): TY PTY PSY QL COOODDOODOO _OgLQ SARA SEA SAG QO OOOSOOS'Y OJ «8 oe eevee ODO ODDWDDODVODO ok OOOOOSOOOOL! 6&@e@e6e8t @ &> o @ OMNDQOONNDO NTT TS eye 6.8 11.0 Mouth 4.2 Fit Torus WNODOWWNADO 4) eee0e7#ee © oe @ @ NEE SESENOD NENG ky OOWGQOONDOO'O @®eoeeeeeresrseee®@ DRA COCORIN. ORL. SO OO9E90ON9O9OO eeee#ee ee @ & @ WMOONND Ete ™ PY BY BS iy QL Ae SYNSDOOOXOO @&e©e8ee28 © 6 6 @ @ NEPRHESENIOD ENE NSE NEN ita ‘ao BWODNWCS V war KRW Cr a en er er | WOOK. COOMQDW OLY) OD iy BDIQOOOHOG!’Y oeesee2e88 8080 @ DMBIDOOWOOO TATE TYEE or09 IOOO5 a Opek 3 RK 3 OO QA Pit WODWYOWQOD® e@®*e@3@e«#3e 8h 8ehmUcOhCUMHMhUCOh hf CI NEED ODO NENAYOYD WOODWWNODQOIOIOS INR IQ OHO WOOO WOWO'NYWOADS e*eeeee8ees @ e DAAAHDOOODO TY Py ry Ww GINS DY KUAWD] cecoeoeeceeeee WEYNQHOWIDOONO eoeeeveeece O10 OOO. cy BNDOMNYOWOSO oeeee#eete @ WOOF DOMNMAAYS TAT Ry Ry yy hy QBHQAWWOOWOlwOV’UYL ® et eee #8 @e@ @ @ NEADODADOIOINN IO WWYWDO'NOOD ee35eeee8 @ @ © © @ DMOOQMODO'QWNOD eoeeeeoeeoee#ee8 ®@ DLP BOP LLWO TATION ON TY 8 &“t ry TY <2 3 wh. ot ™~ Od QR Gam: BWIDOOO99D'H eeeeeoeeeee NPE ANN NRO OOO ' NDOWOOO e®*eee68%¢#@ @¢@ @ INININAR. O0)9N-ON) OUQOQOVWO'HS e@eeeet ees ee WPMONOONYNT TYP MYR ry QL = WWWYOQOYDWDY @eeeteoeeeee @ SESENASAGSEED SEAN NS Wy) LIYROEYNDN YHOO ee 8beeeese#ee es IMWOQDOWOOOYO eo @e8eeeee%e8ee¢ @ CONMOMOMMNDO NAN ON ON my) “Nt ee oO) oO ry (Kk 3 wo h&_ -3 ~ OO Q_&. ae OGODWDOWYOOEOOO YN eee 60e & © & @ 6 ®@ NEPRENCQIIDOIOD NNO 99.996999990 ®@®e ¢ e866 @ ROS OSCR WQOSOS'HA:QS'HY eeeenveeteee@ OOMNMDODOWMIrN™s SS NPY hth WyOd i ee eOCyy oO . ™~ ® mH % Sw 3 Wh 3S © ~ Od ~ QL AE ~ Oo i ONES 2%) Neveeee SY SENDOD YS mM om CvgCVQ OCD NY ” eet ee WOk. OOO 8 KROQ Tycrg cry ® eeese%se QAOMNODO S™Mnw NS Yn ~3 Oo tend ~~ ® KN Q © ® ~~ Le) i wo qQ oO OO LYNZ © eeeee NN SKY S RK Y ~> 8 CQOQ™ OS DWeeveee SOL. OO CO ew “KYD NOK e®ee8s86 ® OnNOny) NNN Py 42 The previous measurements are ail in units of 0.00191 mm. Trans- latine to millimeters then, the measurements are as follows; Pit dtameter O.02:006 mm. Torus diameter 0.01242 mm. Houth diameter 0.00745 mm. Usins the formula Radius squared x 3.1416 to obtain the area, the results are; | Pit area 0.00082 8q. mm. Torus area 0.00012 Sade mm. Mouth area 0.00004 Saemm. Length #30 Diameter 43 No. bord. pits. 196 Pit Diam. 10.4 Torus Diam. 6.2 Mopth Diam. 4.0 No. Simple Pits. 301 Avi Sinple Pit Aree. 2 NOe Tays coréwadd. 8 The penetrable boraeread Average area of Average area of Penetrable area of pits Av. no. Penetrabvle area fe simple Average area of Average no. Simple pit area 18 TABLE IV. Larix bo > Kw Loa) 5670 460 410 5465 27 37 3@ 30 220 217 189 #£=x°260 10.3 11.8 Gi.1 10.4 6.3 7.2 7.3 6.4 4.90 3.6 4.4 3865 427 337 368 8652 3 2 4 3 8 8 5 7 one pit torus of lau. pit pert tracheiad og one av. tracheia pit area is; one pit pits per tracheta per av. tracheia 7 & 420 430 400 40 40 460 193 189 10.3 41.0 9.8 6.86 6.8 6.2 3.7 4.2 3.8 257 246 317 Zz z 2 10 6 4 pit area is; 0.00032 sq. SQ. 8Q- 0.000007 sq. 203_ 0.002156 sq. laricina(heartwood) Penetrance snecimen. 10 Qu. Tie The 400 410 448 8.78560 38 35 36 0.06876 20 32;25 2809 9.7 40.3 10.5 0.02006 6.1% 6.4 6.5 0.01242 3.8 4.68 3.9 0.00745 209 268 808 2 2 2 0.000007 7 "7 " Me Me AMe mM» MMe MMe The penetrable bordered pit area per mm. of tracheid lenéth is 0.01100 sq. mn. The simple pit area for the Same d Unit a 0.000560 SQ. mm.. 14 TARLE Ve Keasurements of 100 bordered pits penetrance specimen from Montana. of tartx occidentalis, Diameters Dtameters Torus Av. of 10 forus Youth Pit of 10 Qv. Mouth Pit BOWOOOOSOEO eeee eet eee NESE NESE WOWOAOYGOS 3 eee © eae & @© @ 6 WN. WO OW DOCON. ODWNOIWWWOOO eeeetf eee 8 PANAMA OQ CQ) TTA TS Pry OWIDWOWOY NOY eeeeeet#ees%se e NHN NEE SEONG Oo DO &QMOwmonnwayh e*Oeeecsveeoestco BRR BDODDAM.O”}O LOYWOLYQIOOO eeeetee8¢@¢@@e @ MYMANTA TYP O-AWOUISOWOUYY) eorceereeeeee NPE NEADS DQOOWIWDNOO'OW ee ®e © @ & @ @ @ CINDER OW OOO WIDMODOOWOODO @ee® © @ @ @4ee¢e TY ENO GORY OQCY TINY ny Qe ae ‘O° LO'NOMDOOYD & @ Pe 6é¢ee6 SAP AGIA NRA YY QO: O~Y%N9990O BO'AWOOLUYOOWNY @evuoeeeeeaeaeé MICE SONA NEVI Cy SSRN OM. BDQNOSBVO9HV9eES eevee aneoces & LOAF SEQ OD NOD DIDO OQ NYO ee¢eeseeeee d INORDAL. OO WOOONWGAYDINS eoceceeteetrtea @ TYNQQOS III MH Nt TAINAN OGOWIDSAQ!'HVO eoteeuetebeeseé QW NEN HOD WWODOIOWYIOO eseueeoebevsdeea WODODHLA.OWWO DWDSDNNYIDWO OM eeeetvteee 6 @ & PAI MONI CVD ma TIS PY PSY WODSOOSOHNOWMY e@e%& @e 6 @ @ 6&6 8 Ca NE NRL N17 NICD SD OMNDBOYMOWMSDS ® eee & e& ee @ 6 OOWDOOSIAIOGUANG eeseeeaebeeoeee DADWADANAAN AMY PYCrD TIT Ry Qe ae QAWMNYOQ9O 4080646 &€ @ 6&6 @ & LDLQ NEN ROLLIN Nt QDQOIQNSSO’9S9 ®0©2#e © ee © &€ @ & @ WK DOWD OWOR MNSDOOBOONOO eoeteeedseoe @ CODY RR CQO ry ASN BN MDWONDONMOINY ® &6ee8e8@ @ & @ NAG“ NR NRIDUDY WNOWNOOWO9'H eee %&tseette8e @ COWR. ODINARNIRLIONN. OUNQOWOWDOODOSD @eeee_eewest&be MYND DONNY Nit NENG Te Re Re By Hy ty ry YO Nt 2 WK DV ~QQ QR Re YVOWDBNMMNOD eee toeeebheo oe LDU NESEY CODWWNOOD' AOD eee et eeebedé BRL. OOO. CORO QOOOBiOUAQAWYS e@o@0e6¢08@6¢6686—6UOGlUhOMUCUO UO MMANAY INNS RII hows; FOL. POLO SKOO ISD eoeeeboe#eeee NE NENENARE NID NSH is as fo Nee eetebhoeeee WALA. COO ORM ODOR ‘Oss 8 KR or a a a a Sr er Se Se Bag CdNANANAQAYINN BETTY ITY Ose egoin The average of the ten for 15 The previous measurements are all in units equivalent to 0.00191 mn, Tranelating to millimeters then, the auvuernges are as follows; Pit diameter 0.02388 mm. Torus diameter 6.01299 mm, Mouth diameter 0.00879 mm. Usiné the formula,. radius 3y.uarea x 3.1416, to obtain the areas, the resulta are; Pit area O.00044 SQ. Nim. Torus area 0.00013 sq. mm. Houth area O.00006 sq. mm. 16 TARLE VI. Larix occidentalis (heurtwood) Penetrance specimen. 1 2 3 4 6 6 7 é 9 Length 48@ 450 590 410 420 510 480 460 455 Diameter 38 42 55 4” 85 56 46 55 44 No. bord. pits. 179 208 3840 240 ezt 240 270 216 1886 Pit diam, 12.6 18.0 12.7 12.1 18.1 12.8 12.6 12.2 12.0 Torus diame7.£ 7.0 6.7 6.3 6.5 7.0 6.9 6.4 6.86 Mouth diam.@.9 4.8 4.7 4.8 4.5 4.4 4.6 3.6 4.8 Now simple pits. 338 292 569 280 248 2:9 424 805 312 Av. simple pit area. 2 2 z 2 2 2 2 2 2 “Chosesd 10 8 10 «8 4 10 10 8 9 The penetrable bordered pit area is; Av. area of 1 pit” 0.00044 8G. mm. Av. area of torus _9.00013_ Penetrable area of 1 av. pit 0.00031 Sq. mm. Av. now pits per tracheta Penetrable area of l' av. tracheiad The stmple pit area tis; Av. area of i pit Avi no. pits per tracheiad —_ Simple ptt area per av. tracheiad The penetrabtle bordered pit area is 0.01798 SQ. MM, a 236 0.07316 sq.. mm. 0.000007 Sq. mM. 0.002576 sqe mm. per mm, 10 620 55 262 12.9 666 17 QUe 486 47 868 of tracheid length The simple pit area for the same unit is 0.000630 sq. mm. MM 4.10670 0.08977 0.028876 0.012988 0.008786 0.000007 17 fhe figuees gtven in Tables III, IV, V, and VI verify the prelin- inary figures of Tables I and II. The penetrable bordered pit areas siem ta be the anlty factors which akhow a consistant relation to the penetration figures. The simple pit areas... vary from 0.000469 Sqe ™™. to @.000560 sq. mm. in the same species.ana there is no evidence elsewhere that the simple pit area ts a factor in the penetration of presernatives into wood. Summary of kesults. In the case of Larix laricina and Larix occidentalis we have two species very similar in most of thetr characters but dissimilar in those structures most concerned in the passage of creosote oil into wood. Thus the seeminé paradox in penetratton, upon close examination of the bordered pit structures, is explakedd by a aifference in "pen- etrable bordered pit areas"... Whether the figures which I have obtain- ed in the careful measyrements of one humared bordered pits will be found true in all cases remains to be proven. It woulda be interesting to pursue this question of "penetrable bordered pit areas” thru all the woods which are trziated commercially in ord@r to see whether the relationship between penetration and pen- etrable areas will hold in other cases besides the one tnvestisated. In the appendix I have incluaed studies of several other kinds of wood, different species of Pinus,and one of Abies. fhe penetrance figures for all of these have not been ascertained. Their main value lies in the penetrable bordered pit areas per millimeter of tracheid length which ts ¢given for each. Of cours? a comparison betwen two species with several points of structural difference 18 will necessatate a careful aifferentiation between each pair of noints involved.. In the case of the two species of Larix discussed the spe-+ cimens were very similar excepting in bordered pit area which was penetrable by preaervatives. In comparing Abies to Pinus it would be eecegsary to allow far the fact that most forms of Abies have no resin passages while they are frequent in Pinus. fhus for purposes of comparisan species should be assoctated which have only one ora few points thet are not common to both. In many cases the heartwood of a spectes is harder to genetrate than the saywood.. Since tin the higher caontfers the tracheids, which are the passage ways,are seldom found to cantain resin, the cause of this difference can scarcely be assumed as a clogsea conditéon of tracheias. Here then is a case where there are no,. or few, structural differences,ana still a dif- ference in penetration. The appendix also contains a table showing the results of a few penetrance tests which I have conducted in an endeavor ta check the figures on Ll. laricina ana L. occidentalis égiven by Teesaale (1). there they vary fram his, the error, if there be one,. is perhaps due to the imperfections of my apparatus,. a pieture of which will be fauna in PLAT? XII. (1) (4) 1g Literature cited. Teesdate, C.#. Lelative resistance of various conifers to injection with creosote. U.S. Dept. of Agr. Bul. 101. Woashington.. Sept. 1914. Penhallow, D.P. A manuat of the North American Gymnosperas. Ginn and Co. Roston. 1907. Railey, I.W¥. fhe preservative treatment of wood. Forestry Quarterly. Vol. 21. 1913. Teesdale, C.H#. The absorption of creosote by the cell wails of wood. U.S. Forest Service Cir. 200. APPENDIX Cantatning tables of measurements on eight species of Pinus and one species of Abtes. Also penetrance figures on Larix laricina,. Le. occidentalis, and several miscellaneous srecies. Pinus strobus, specimen from Michigan. 1 2 3 4 o 6 7 § S 10 au. Length 454 637 300 685 550 285 812 325 350 410 412 Diameter 286 27 19 21 22 20 25 £20 20 30 23 No.. bord. pits 118 153 91 120 117 52 61 56 35 50 85 Pit diam. 8 8 10 10 10 9 10 10 10 11 10 Torus dian. 4 4 6 5 5 6 6 6 6 6 5 Mauth dian. 2 2 3 3 3 3 4 5 4 4 3 No. simple pits. 15 18 4 14 13 10 7 8 7 20 12 Av. simple oo . a | pit area. 81 60 70 90 90 +70 100 90 100 100 85 No. rays crossed. 5 "7 2 5 4 2 3 8 8 6 5 The penetrable borcered pit area is; Av. area of 1 pit 0.00025 sq. mm. Av.. area of torus ___ 9.00007 sq. mm. Penetrable area of 1 av. pit 0.00022 SQ- mM. Av. no. pits per trachetada eee 65_ Penetrable area of an av. tracheia 0.01827 Sq. mn. The simple pit area is; Av. area of 1 pit 0.00031 Sq. mm. Au. no. pits per tracheia ___----12_ Simple pit area per av. tracheid 0.00372 8q. mm. The penetrable bordered pit area per mn. of tracheia length is 0.00504 sq. mn. The simple pit area for the same unit is 0.00107 sq. mm.. MM. 8.48140 0.04302 0.01910 0.00955 0.00573 0.00031 it Pinus lambertiana,. specimen from California. 1 2 3 4 5 6 7 8 9 10 au. Mie Length 650 670 610 800 770 910 690 5 €40 640 707 5.97415 Diameter 38 34 60 37 42441 #38 386 40 40 21 487 0.07067 No. bord. pits 215 245 245 2096 208 822 300 260 210 162 2389 Pit diam. 11 11 12 12 #12 «#«18@«©122«©12@«©612«612+2+~¢«a12—”stié«i iw RB Torus diam. 6 g 7 6 6 6 6 7 6 6 6 0.01146 Mouth diam. 3 4 6 4 4 4 4 5 4 4 4 0.00764 NOgy simple no 61 52 86 564 51 49 49 #474 48 ~ «659 Av. simple pit area. 45 45 43 55 45 30 40 40 40 40 42 0.00015 No. rays qrossed. 7 7 8 13 11 13 7 8 8 6 9 The penetrable borderied pit area is; Av.. area of 1 pit 0.00038 sq. mm. Av. area of toeus __- Gp 0001 1_ sq. mm. Penetrable area of 1 av. pit 0.00027 sq. mm, Av. no. pits per tracheitad ______ £49 Penetrable area of an av, tracheta 0.06382 sq. mm. The simple pit area is; Av. area of 1 pit 0.00015 sq. mm. Auvl. no. pits per tracheta ee og Simple pit area per av. tracheta 0.00904 Sq. mm. The penetrable bordered pit area per millimeter of tracheia lenéth is 0.010&0s sq. mm. The simple pit area for the same length is 0.00150 sq. mm. tit Pinus monticola, specimen from Cam.. Woods Length 700 7606 710 710 720 Diameter 91 35 30 29 45 No. bord... pits. 121 125 115 140 240 Pit diem. i2 13 12 13 12 forus dian. 6 6 6 6 6 Nauth dian. 4 4 4 4 4 No. simple pits 40 43 39 42 80 Av. simple pit aréa. Ze 28 30 30 50 Na. rays oro378e ad 9 9 8 8 685 610 600 37 25 25 140 178 1565 12 11 p 60 46 40 30 40 40 The penetrable bordered pit area is; 4uvu. area of 1 pit iu. area of torus Penetrable area of an au. pit Av. no. pits per tracheta Penetrable area of an au. tracheiad The simple pit area is; Av. area of 1 pit Av. no. pits per trjacheid Simple pit aréa per au. tracheia 0.00038 sq. 0.00011 sr 0.00027 sq. —~----122_- 0.041389 sq. 0.00014 sq. ------- Dd 0.00768 sq. 860 30 198 13 81 50 13 MM. MMe MM « mm. mM. MM « of U.S. 10 au 450 675 30 32 146 156 12 12 6 6 4 4 44 54 BO 39 6 9 mm 6.70375 0.08112 0.02292 0.01146 0.00764 0.00014 The penetrable bordered pit area per millimeter of tvjacheta length ws 0.00729 sq. mm. The simple pit area for the sma length igs 0,00133 Sq. mm. ty Pinus resinosa, specimen from Com. Hoods of U.S. 1 2 3 4 5 6 7 8 9 10 av mM. Leangth 500 4650 400 360 410 3665 350 420 860 355 8397 3,85465 Diameter 28 32 22 2i 25 23 25 21 24 26 25 0.04775 No. bard. pits 87 B84 71 76 IOd 67 63 73 BO 107 719 Pit diam. 10 10 10 10 12 10 1c LO 10 11 10 0.01910 Torus diam. 8 5 5 5 6 6 6 6 5 6 6 0.01146 Mouth diam. 3 3 3 3 4 4 4 4 3 4 4 0.00764 No. simple pits. 15 14 14 14 ” 19 22 7 17 10 14 Av. sinmryle pit area. 50 50 50 50 50 50 BO 60 40 70 50 0.00018 No. rays cromsecd 5 4 3 3 2 e 6 2 6 3 4 The penetrable bordered pit area is; Av. area af 1 pit 0.00032 sq. mm, Av'. area of torus --%290011 sq. mm. Penetrable area of 1 au. pit O.0U020 sq. mm. Av. no.. pits per tracheia 79 Penetrable atea of an av. tfacheid 0.015&& sq. mm. The simple pit area is; Av. area of 1 pit 0.00018 sq. mm, 4v.. now pits per tracheid 2g. Simple pit area per av. tracheid 0.00255 sqe mm. The penetrable boraevjeqd pit area per millimeter of tracheta length is 0.00460 Sq. Miri. The simple pit area for the same lehgth is 0.00074 sq. mm. U Pinus divaricata, sagwood; specimen from 1 2 3 4 5 6 7 b Length 860 260 290 240 370 290 3190 290 Diameter 20 ZO 17 25 23 20 20 20 No. bard. pits. 50 414 42 48 96 48 V& 69 Pit diam. 10 10 10 10 190 10 10 10 Torus diam. 6 6 6 6 6 6 6 6 Mauth diam. 4 4 4 4 4 4 4 4 Noe simple pits. 46 37 19 48 24 43 BZ 38 Av. simple 6 pit area. 10 8 8 8 10 10 8 No. rays crossed 5 3 3 5 5 4 4 3 The yrenetrable boraered pit area is; Av. area of 1 pit 0.00029 sq. Av. area of torus ___9.00011 sq. Penetrable area of 1 au. pit 0.00018 sq.. Av. no... pits per tracheia ~~. GL_ Penetrable area of 1 au. tracheia 0.QG1098 sq. The simple pit area is; Au. area of 1 pit 0.00003 sq. Av. no. pits pen tiacheid —________ 32 Simple pit area per av. tracheid 0.00107 sq. Maaison Laboratory. 330 20 83 10 17 MM. MM » mM. MM « mm, MM « 16 410 20 69 10 76 au 314 20 61 10 37 The penetrable borderea pit area per millimeter of tracheta lenéth is 0.00396 sq. mm. The simple pit area for the same length is 0.00042 sq. mm. MN: 2.85330 0.086820 0.01910 0.01148 0.00764 0.00008 Pinus palustris, Length Diameter No. bord. pita@. Pit dian. Torus dian. Mouth dian. Noe simyle pits. Av. simple pit area No. rays crossed 700 35 208 12 82 45 510 35 205 14 20 45 700 35 190 12 99 45 vi heartwood; specimen from Com. 720 37 280 128 56 40 650 28 108 13 64 30 740 710 680 35 30 30 162 180 208 12 12 12 129 79 54 45 30 35 12 8 6 The penetrable bordered pit area is; Av. area of 1 pit Av. area of toeus Penetrable area of 1 au. pit Vo. of pits per av. Fenetrable area of 1 au. Simple pit area is; av. area of 1 pit Au. no. pits per tracketa Simple pit area per cv. The pernetrable bordered pit area is 0.0C792 sa. The simple pit area for the same lensth is mM. tracheia tracheia tracheia 0.00035 SQ.. 4, 90014_sg. 0.00024 Sq. ~----§-129_ 0.04560 sq. 0.00015 sq. 0.01050 sq. 700 32 188 35 50 mM. mM. M™ « NM « MM « MM « per millimeter of woods of U.S. 10 800 42 187 12 83 45 au 6OL 34 190 12 70 41 MMe 5.88895 0.086494 0,.02)292 0.013837 0.00855 0.00015 tracheia length 0.00160 sq. MM. vii Pinus glabra, sapwociu(?) , specimen from Madison Laboratory. Length 440 435 425 350 340 Diameter 26 27 27 30 30 No. bord. pits. 74 73 67 BL 68 Pit dian. 12 12 12 12 12 Tarus dian 8 6 6 6 6 Mouth diam. 4 4 4 4 4 No. simple pitéd 31 28 27. 86°23 17 A4'v. einple pit area 15 Plate x PLATE XII. The apparatus used tin the penetrance experiments, consisting af a reserve cylinder above fer use in case vacuum ts first desired, and the pressure cylinder below. A ptece of wood is shown tn pasi- tion between the metal plates which hala it to the pipe leading from the pressure cylinder. The wood has a hole bored in the farce which fits over the tip of the nipe coming thru the plate fram the cylinder. This hole affords the penetrance surface... Apraratus modeled somewhat after that of Teesdale. (see U.S.D.A. Rul. 101 ). oy 7“ - 4 ” -¢ oe. - oe oy “e om v .- w ' - vv. er oS > “) eo” » - un A al . - a 78 _ . a oa e ” \ - ~ - . 7. vid ~~ ‘ : e s - .- —_— 7 4 - r a - a. - a . e » a w . . ~ .¢ As = e - e “fF é a : . “+ , . ‘ 1 a” o -” ° ° ! . y ~ y . omer . 7 ia , m4 ~ if iE - k F 7 - a | = Lb | \ =| at Ky. ia | od TP 4 - a Plate XII.