This section is from the book "The Gardener's Monthly And Horticulturist V20", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Mr. Francis Darwin has proved very conclusively the truth of his father, Charles Darwin's position, that the so-called carnivorous plants do make use as food of the plants they catch. A large number of plants were fed on meat, and as many on what they could get from the earth as best they could, and the difference in growth and final product were very much in favor of the meat-fed plants".
The above I cut from a contemporary Journal. Resolving to fairly test the correctness of Mr. Darwin's theory, I last season procured in March, from Keenansville, North Carolina, a large number of Dionoea muscipula (Carolina Fly-trap). The plants arrived in fine condition, and I resolved to test fairly, on a large scale.. the correctness of Mr. Darwin's conclusions. Selecting from the lot two hundred of the strongest plants, I thoroughly rinsed them again and again in water, so that every particle of soil and all other matter foreign to the plants was removed. I then procured two boxes, three feet by three feet, and three inches deep; these were filled with Moss (Sphagnum) and sand mixed, in about the proportion of four parts Moss to one of sand, forming a soil somewhat similiar to that which they had been growing in naturally; this compost had been also subjected to the rins-sing process so as to clear it from impurities. One hundred of the Fly-traps were planted in each box, the plants selected being as nearly alike as possible. After planting, the boxes were each copiously watered with pure water and placed in a cool and partially shaded greenhouse. One box was covered with a wire netting, as fine as could be procured, so as to exclude insects; the other was left uncovered.
By about the middle of May, two months after planting, the plants had begun to grow freely, and the "feeding" process was begun with the plants in the uncovered box. In this, I was assisted by Mr. William Tait, one of my neighbors, a gentleman of leisure, and one who is well versed in many branches of natural science; between us, the one hundred uncovered Fly-trap plants, were " fed " almost daily for three months with flies and other insects. In August, three months from the time the feeding began, the operation was stopped, and the most careful examination and comparison failed to show the slightest difference between the one hundred plants that had been "fed, " and the one hundred (under the wire netting) that had not been "fed, " both lots had made a splendid growth, and were the admiration of scores of visitors. I never omitted an opportunity to ask professional horticulturists visiting us for their opinion, and the verdict invariably was that both lots were identical, as near as could be. In this case, the "feeding " certainly did not fatten.
It may be that our American flies were not so nutritious as the English " meat, " though certainly ours was the more natural food of the two, but as corroborating the test of Mr. Darwin, it completely failed.
"What we are all after is the truth in this matter, and in case my experiment may have been in some way defective, or that the prejudices of myself and friends against a theory that seems to reverse the whole order of nature, may have in any way influenced our judgment, I will be most happy to furnish, without charge, to any dozen readers of the Gardener's Monthly, who have the proper facilities to make the test, a sufficient number of plants of Dionoea muscipida, to further demonstrate the truth or falsity of Mr. Darwin's conclusions on this subject.
I had rather a ludicrous incident occur in relation to this matter. My friend, "Wm. R. Smith, superintendent of the Botanic Gardens, at Washington, who is a thorough believer in the carnivorous plant doctrine, being at my place last Winter, after the above experiment had been tried, we got into some controversy on the subject. Now, Mr. Smith is not only one of our best botanists, but his knowledge of general horticulture is perhaps second to none in the United States; moreover, he is a perfect Wilber-force in eloquence and argument, and having driven me pretty well into a corner, he almost squlched me by taking a magnifying glass from his pocket and showing me beyond question a minute species of shell-snails embedded in almost every one of the closed up leaf traps of the Dionoeas. "There," says he, "nature has placed the food - the animal food - direct into the mouths of these insect-eating plants. Can you longer doubt the correctness of Darwin's theory ? " I was staggered but not yet convinced, and resolved to keep a close watch on the shell-snails " that nature had placed in the mouths of these insect-eating plants." Very soon they required no magnifying glass to see them; in three weeks they had increased wonderfully in "breadth and stature;" in three weeks more the biters were bitten, for the snails had eaten the Fly-traps almost completely up! Mr. Smith has, probably somewhat changed his base on the subject of " carnivorous plants," particularly as regards their use of shell-snails as an article of diet.
Mr. Francis Darwin has proved very conclusively the truth of his father. Charles Darwin's position, that the so-called carniverous plants do make use as food of the plants they catch. A large number of plants were fed on meat, and as many on what they could get from the earth as best they could, and the difference in growth and final product were very much in favor of the meat-fed plants.
A Salem, Mass.; correspondent kindly says:"Find an important error, March No., page 87, Ed. Notes, fifth line. Should have been insects not plants." The worst of it is that the editor cannot put the mistake on the "compositor," for it fell carelessly from his own pen.