This section is from the book "The Gardener's Monthly And Horticulturist V21", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Miss S. S. K., asks: " The question ' how are plants protected from animals and unfavorable weather?' was referred to me by a botanical class to which I belong. I suppose, of course, it means naturally and not artificially. Small plants are protected by snow and in the forests the fallen leaves serve to keep them warm, but how are the larger ones protected from the weather, and how are plants generally protected from animals? Can thee refer me to any botanical work which contains information on the subject? Would such things as thorns, the sting of the nettle, etc., etc., be considered as a protection to the plants?"
[Many plants get some protection from fallen leaves of taller trees. Others protect one another by growing together in forests or groups. The chief power of protection is by their own internal power to preserve an even temperature, their vital power - just as animals have a similar power, though, also as in animals, unusual external causes will induce them to part with that heat and die in consequence. The exact range of this life-preserving heat in plants has never been determined that we know of. Some plants part with their life-preserving heat on the first white frost, while others can keep their juices from freezing even when the temperature is far below zero, just as animals can. In regard to protection from animals, it is just possible that thorns and other contrivances may have some slight influence, but the spiny thistle is browsed on by the ass, and the pony kicks open the cactus on the desert for the liquid it contains. Most likely the great exuberance of nature which makes infinitely more vegetation than there is animal life to feed thereon, is the chief "protection" to the continuance of vegetable life in all its varied ! specific forms. - Ed. G. M].