ll ill | | | | | tii | | z83 || MTC 3 1293 10768 8123 LIBRARY | Michigan State University MSU RETURNING MATERIALS: ace 1n book drop to LIBRARIES remove this checkout from a your record. FINES will be charged if book is returned after the date Stamped below. MAGIC & v4 NOV 0° 1998 SLNICR AGRICULTURAL TtnSIsS. "THs GROWTH: Cr SEEDS" MARY C. BAKER. Mishigan Agricultural College ,1898. af. THESIS THs GRCWTH CF SEEDS. The object of the experiments carried on was to ascertain the manner in which the seeds of the different vegetables freed themselves from the send-coat when germinating. The nine kinds of seeds experimented with furnish examples of nearly all the forms of cotvledons to be fourd amons the cul- tivated vegetables. They were squash,black lima and bush beans, Sweet corr,peas ,toinato,rudisn,bveet and onion. The corn and onions represented the nonocotrledonous und che others tne di- cotvledonous plants and tre beans and peus furnisneda exarnnles of fleshy cotrledors. The seeds were planted ir. boxes,one side of which wus a glass slide ,und drawines were m.ae at irtervals of two or ifftesr- Qu ae tnree dayS,ucceording to the rarniditr of grarth au une Pm Siuges of develovmernt unm to tne time when treo first curve leaves aryewred. an the ocuse of the Lurger seeds trnev vere Planted in dif’erent vositions und at depths varying fron one- Toiurth to two incres. Tre depta of covering did not have a verr murked effectjexcenting in the time of apveurance o* the plent,- those nearest the surfuce usually anrearing about a dav earlier than those weian were cavered ore aml a hulf to two incres. The nosition Of che secgyhoweveryhald a marked effeart in most Causes excene those Of tre hHeet ans onion weere it ‘vas not verr appurenmte Imone instance ,(Fis,.° IV) tre entivledors of a ker- nel of corn which had been pluntend with tre noint upvard,esrew Gowrverdyanier the seedyurd wo on tre otner side,very neurly 93828 (2) encirclir.= itv. fhe maunmrenr in which tye eotrlesons freed themselves Prom tre seed cout differed creatly in most of tre kinas of seeds. Fig. 222F. In the squas’ uw Siall rrojectir cr Fro.k,jJ it udvove the root, Cuughnt tne edee of tne oucver covering und neld it firnly down wnile the cotvledons grudually drew utward und out. The empty shell remained for some time attucned to tre hook;butrt finally became dislodeec und cdisupveured. In one ca.seyvhere tne seed was Dlanted with the voint downvward,the hook wus nou brought into a vosition were it wus uble to hold tre seedocoat which waS curried ubove tre fround with the cotyledons still en- closed,-ore being entirely unl tre ouher about nulf covered. The portion of the cotrledon which was outsid of the seed- cout grewia verry Little ard the thickness was mach greater tran that of the rormul cotvledors. In the vnortiorns which remained covered,there was no develsvment wratever and the cotrledons becume vellowisn-brown und verr brittle. The erowth of the nlant wus very Slow,t»e increased size during one week being very little more thun that of un ordinary plant im one dur. The ei 9Ff the seed-cour. was tne Same in both kinds of means othe thin outer coverinre be oume crucked across in sev- eral pluces br the expunsion of the cotrledors und was arpar- ently rubbed off us the nlamt pusked itS wav through tne soil, being entirely sone by the tine the plant reached tme Surface. ————a ~ the cotyledons of the corn musnet asice tre portion of the seej-cout which covered the germ,leaving tre remainder intact. (<5) The seed weich remained attucned to tne plurt for some time, gradually becume shrunken and withered and finally disavveaur- ede In the neus,tne cotriedons of which remained under eround, tre seed-coat was somewrut broken but remained on the seed. Fie. YW. Tne seed-cout of the tomuto vus opened at the noint,the root foroine ite wuy out first und the cotvriledon gradually with- dravineg. In some cuses tne seed-coat reruineda uttached to the Fie 3 YZ root of the pluntjout us a usual thing it was curried to the Surface of the eround by tre cotvledons before thev entirely freed themselves from ite Tne aentrh at which the seed was Planted influenced this ereutlve Seeds which were planted from one to one urd a nulf incnes deen were much more liable to leave the seed-coat attaacred to the roast than tose planted less deeplyyyvyile tnose planted just below tre surface almost invariably brousmt vhe seed-coat above tne Ffround. Ir. the radish the seed-coat wus first broken br the root Fie lV | Fig 3/7. then grudually split anart ane forsed off DY the expnunsion of the cotvledons. The nheet seeds Somewrut resembled vere Lomuto seeds in the manner Of their germination, esnecially in tre wur the ceotvle- dons wits irew Prom the seed-cOut and in their terndenev to ecarry it ubove fround ywrnich wus rather sprewtier tran in Lhe tomato seedling,-tne seed-coat often remuinine attached to one of the cotvledons for some tine after trevr unfolded. In the case of tre orion the root forced its war through (4) the seed-oout in mich tine sume runner aS t1e tomato; the seed- cout ,rowever, remaining fixed on t»e seed until tne nlant had made wu oonSideruble erovwin. Fos. In tne tomato,beet, onion und rudisy there wus,to0 a certain extent,a Similarity in the way in weich the outer coverirgs of the speed wus thrown off. Amone tre lurrer seeds, however, there was Little or none of tris,excevt in te bei.ns and this Walt u cuse where ou Similaritv of erowth would be almost inevit- able. Tere was a1lSO a certuin deeree of Sintiluritr of erowt* 11, Sone of the young plants but the kinds were too widely sen- arated to show anv greut likeness. : if He belay caricd { J. Wed ATEE Ee Ye ceed cred amd. forever 4° oe le Yi bork AM with | fo ac yet tie A 2 AL Lek shag tha seco J Lolth Paflll Z 3 Ie, gh Del id ye “C1 coty alone an fehl “Sy feel ever thar ae los | $ehbowiy ates He 4-5 GL, wd: GE nt gs len oi ( LEBEL Ly wh tome bom L bilidre ae Sega ri y wih Gb iichy thugta ji Hi fosuloip S: WLS wat GV. hare wm plaled. aw. acd oval hht blr. ae dh. Wud Cares | Ah dL hated foc <¥ clonrvenal, LAMhonL which was by a ater AT ore 3, Abeta Rize 2 CL Po pn fot 4 GOL, kc thvvree rte Ayn d Phe rt hdloma tote Lll nell d. Wh eet hone orm tA wth baer Sth Kle+ rhe fon 1G, dart bubdip the 7 8. ih (pee tae ua Tf Josncny J 7 Lo grocl pro . Cad erat Aeljledon. 0. Ket Mn. TT GL Lt a | elt fies — 4 oe 3 De oF ace alecled F co EE 3 {IA y+ b L~ g- pA) * , p | A 6 betel, — C C. Rovt dh. Gouse Leavea 2 Dnt fe. 8 Weg Whe Ze fla hae tgs GEMS Lh a, Geek card b bh bela es ne a a, 3h let onth Ha aie ttl fed ba a S$: Aacdeintadbering B Lap lte ” b. Mdybedone, 0. Reb d. £34 b: Lokv ath ser nby hy fj MICHIGAN STATE UNIV. LIBRARIES VAMC ANNNU0N 31293 107688123