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PLANTS THAT HIDE FROM ANIMALS.
NUMEROUS instances in which the habits of growth of certain plants serve to protect them from destruction by animal enemies are recounted in The Popular Science Monthly (New York, June) by Prof. W. J. Beal, of the Michigan agricultural college. Some plants, he notes, are thus protected by growing under thorn bushes and thistles. He writes:

"C. G. Pringle, for many years a famous plant collector, especially in Mexico and the arid regions of the United States, speaks
of a native grass of Northern Mexico, Muhienbergia Texana, as
such a great favorite with all grazing animals that it is usually exterminated or nearly so, except when growing under the protection
of thorny shrubs, usually mesquite bushes. In Arizona during
the winter and spring, the Indians bring it long distances into the
towns to sell. He adds: 'How many times I have contended
with the horrid mesquite bushes to gather an armful of this grass
to carry joyfully to my hungry and jaded horses.' In such cases
the thorns, spines, and perhaps bitter taste of the bushes not only
protect the young growth and leaves of certain plants, but furnish
shelter for other tender and nutritious herbage.
"In arid regions, especially, similar instances of protection by
thorn bushes are numerous."

Again, some plants retire beneath the surface of the ground at
the close of the growing season, especially in regions subject to
droughts or cold, remaining secure beneath the surface for months
in the form of bulbs, tubers, and rootstocks. At such times they
are nearly sure to escape destruction by animals, Examples are
Solomon's seal, Dutchman's breeches, May apple, goldenrod, and
artichoke. Other plants are protected by water, and of these Professor Beal says: 

"Not only the flowers of many species of plants as they project above the surface of the water are protected from most unwelcome insects, but the whole plants as well. Mud turtles, certain fishes, water-snails, larvae of insects, eat aquatic plants, but most other animals are unable to reach them in such places.

[Illustration] Four seeds which closely resemble pebbles, Among which they were accidentally gathered.

"Water-plantain, wild rice, pond-lilies, arrow-head, pickerel-weed, pond-weed, lizard's tail, bulrush, bur-reed, cat tail flag,
water-dock, and many more of their associates, root at the bottom
with leaves floating on the surface or projecting above.
"Innumerable low forms, known as algae, are at home in lakes, ponds, and streams, or on the surface of the water, while other kinds thrive in salt or in brackish water.
These aquatics find protection below the surface or by extending above it, not only from numerous animals, but they have no competition with others which can only grow on dry or moist soil.

A NIGHT BLOOMING CEREUS,
Showing large succulent roots which serve as a storehouse for water (Much reduced).

"Aquatics and marine plants and algae
are also protected from extremes of cold and heat. During the winter of a cold or temperate climate the rootstocks and buds severed from the tips or

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branches, and even the entire plant of some species, remain safe
and dormant in the mud at the bottom, ready on the approach of
mild weather to begin growing again. Some are amphibious, able
to thrive when the land is Hooded or when the floods have subsided.
Plants with such habits have little competition.
"A few plants not only defend themselves, but are aggressive
fighters, because they put to good use the animals they capture.
The bladderwort is a water-plant and catches much of its food.
Underneath the surface of the water in which the plant floats are
a number of lax, leafy branches spread out in all directions, and
attached to these are large numbers of little flattened sacks or
bladders, sometimes one-sixth of an inch long. The small end of
each little bladder is surrounded by a cluster of bristles, forming a
sort of hollow funnel leading into the mouth below, and this is
covered inside by a perfect little trap-door, which fits closely, but
opens with the least pressure from without. A little worm or insect, or even a very small fish, can pass within, but never back
again. The sack acts like an eel-trap or a catch-'em-alive mousetrap. These little sacks actually allure very small animals by displaying glandular hairs about the entrance. The small animals are imprisoned and soon perish and decay to nourish the wicked plant."
A curious case of protection by hiding is that in which the
plant deceives man himself by masquerading as something that it
is his interest to preserve. Thus gardeners often overlook certain
weeds that resemble the flowers or vegetables with which they
grow. Says Professor Beal:

“It is the exception to pass over a bed after a workman has
'dressed it up' and not find a number of weeds left among the cultivated plants. They are overlooked because of some resemblance of the weed to the plant desired. I enumerate a few examples found one day in the month of May: A few wild onions
are left in the asparagus; wild seedling lilies in a plat of Solomon's seal and in a bed of turtle-head: June grass lurks in plats
of several sorts of pinks, of Phlox, and of many other plants;
narrow-leaved dock is often abundant, and some of it is left in a
plat of dandelions, of teasels, of rhubarb, of buttercups, of rue
anemone; pig weeds are left to go to seed among potatoes and
tomatoes; the brittle joints of prickly pear are left to grow among
other species which they resemble; seeds of violets in variety
spring up in plats of other violets where they were shot by the
mother plants."

Among other cases of protective imitation that results in driving
away or deceiving animal enemies Professor Beal describes the
following:
"In portions of Washington rattlesnakes are very abundant, and
are much dreaded by cattle and horses which graze large portions
of the State.

"In this region grow large quantities of Iris Missouriensis and
when ripe the rattle of the seed in the pods closely resembles the
rattle of the snake. Grazing animals invariably step back after
hitting these pods, and thus the green leaves of the plants are
spared to work for future crops of seeds.

"Seeds are frequently met with that are mottled or striped or of
an inconspicuous color difficult to find when dropped on the soil
or among small pebbles. Seeds of this character are least liable
to be destroyed. By a process of selection for many generations,
no doubt, seeds have acquired their present colors, and some of
them are still undergoing this process."