THE LANCASTER FARMER. 



CARNIVOROUS PLANTS. 



There are no doubt many intelligent people, 

 and some scientific people, too, who may be 

 somewhat startled at the coupling of a term 

 with subjects of the vegetable kingdom, that 

 is almost universally believed to be applicable 

 to the animal kingdom alone. But we have 

 fallen upon a veiy progressive period in science, 

 religion and literature, as well as in philosophy, 

 mechanics and agricultiu-e, and perhaps no 

 department of natural science has been so 

 thoroughly explored as that including botany 

 and vegetable physiology. If the question 

 involving the capture and assimilation of ani- 

 mal food b}' certain species of plants, has not 

 been determined in the a'ffirmativc, at least 

 sufficient progress has been made to save it 

 from an unqualified negative; for observations 

 have been made by learned explorers, whose 

 experiences and logical conclusions cannot be 

 successfully ignored, nor satisfactorily ex- 

 plained upon any other hypothesis. 



When Dr. Erasmus Uarwin — the grand- 

 father of the author of the "Origin of Species" 

 — about one hundred years ago, published a 

 work on "The Loves of Plants," he was as 

 much laughed at for its strange theories as 

 ever Harvey was when he first announced his 

 theory of the circulation the blood ; but the 

 subject of consciousness and volition, which 

 he attributed to certain species of plants, is 

 not now considered so fantastic by learned 

 men as it was when the elder Darwin wrote ; 

 and in our day it is becoming manifest, almost 

 beyond a cavil, that paralysis of a plant can 

 be produced by external injury ; that the ex- 

 istence of a nervous system in many vegeta- 

 bles is capable of a satisfactory demonstration ; 

 and that some flowers, at least, display their gor- 

 geous colors to attract certain species of iusects; 

 and that without this arrangement the pollena- 

 ceous impregnation of certain plants could not 

 possibly take place ; and that some plants do di- 

 gest and assimilate animal matter. In the Scien- 

 tific American for Dec. 22, 1874, page 9, seven 

 species of these carnivorous plants, belonging 

 to as many different genera, are very cleverly 

 illustrated ; namely, the "Trumpet Pitcher," 

 or "Side-saddle Flower" [Sarracevia vario- 

 Iciris) which, with the allied species purpurea, 

 according to Dr. Gray, are found growing in 

 the United States, from New England to 

 Wisconsin, and flower in June. The for- 

 eign "Pitcher plant" {Nepenthe dintillaria) 

 which grows wild in China and the East 

 Indies generally. " Venus fly-trap" (Dirmcm 

 rtuiseijmla) in the savannas of North ( "arolina 

 growing wild. The "California Pitcher" 

 {Barlingtonia hrachyloha et gJandulosa) which 

 are found in the mountainous regions of the 

 Golden State, and flower from June until 

 August. The " Butterwort " (Pintjuicida vul- 

 garis) found from New York to Lake Superior, 

 and northward, in July. The " Sundews " 

 (Brosera), of which there are several species in 

 America, namely, the " Long-leaved Sundew " 

 (D. longifoHa), the "Round-leaved" {£). rotun- 

 difolia), the " Line-leaved " (D. linearis), and 

 the "Thread-leaved Sundew," {D.Jiliformis). 

 Also a species of Cephalntvs, which is gen- 

 erically allied to Dioncca. The Drosera rotun- 

 difolia — "Pound-leaved Sundew," occurs in a 

 swamp near Sniithville, Lancaster county. Pa. 

 In addition to the foregoing there are a num- 

 ber of plants commonly called "sensitive 

 plants," including the "Sensitive Briar" and 

 "Sensitive Fern," which, if they do not capture 

 and approjiriate the liquid substances of insects, 

 yet they immediately collai)se or close their 

 leaves and droop their branches when any 

 object comes in contact with them ; or as soon 

 as darkness supervenes, either at nightfall or 

 in the absence of the sun during the day. M. 

 Dutrochet, after a series of minute and care- 

 fully conducted experiments, believed that he 

 found the true nerve motion of these plants, 

 which he attributes to the agency of the sap 

 alone, and he considers the power of locomo- 

 tion to depend upon its system of nervous cor- 

 puscles in the ligneous part of the plant through 

 certain tubes supplied with these nervous cor- 

 puscles, and that neither the pith, the bark, 



nor even the cellular tissues, have anything to 

 do in detenuining the motion of the plant. 



But it is of carnivennis 2jlants that we had 

 proposed to make some nienlion, and not those 

 that are merely sensitive plants, especially as 

 these involve questions bearing on Entomo- 

 logy, as well as on Botany. More than thirty 

 years ago a Mr. Ellis first divined the purpose 

 of the capture of insects by the JJiona'a; but 

 it was the Rev. Dr. Curtis — a most practical 

 writer on Entomology — who made out the de- 

 tails of the mechanism of motion by ascer- 

 taining the seat of sensitiveness in the leaves 

 of these carniverous plants, and he also pointed 

 out that their secretions were not a mere lure 

 exuded before the capture of the insects that 

 visited them, "but a true digestive fluid, 

 poured out, like our own gastric juice, after 

 the ingestion of food." In 1808, Mr. Canby, 

 an American Botanist, revived the subject 

 of this wonderful plant, (Venus's Fly-trap,) 

 after it had slept for a full generation in 

 statu quo ; and he is still engaged in his 

 botanical researches. To facilitate his labors 

 he located himself in the Dioncra district, and 

 carefully studied the points which had been 

 made out by Dr. Curtis. By feeding the leaves 

 with small bits of fresh beef, he found that they 

 were completely dissolved and absorbed, the 

 leaf opening again with a dry surface. Cheese 

 disagreed with the plant, and finally killed it. 

 He also gives a very interesting account of a 

 captured curctdio, which used all its power and 

 cunning to escape, but it was of no avail, it 

 finally became enveloped in the digestive fluid 

 and died. This fluid, he maintains, is an 

 actual secretion, and not the result of the de- 

 composition of the substance which has been 

 ca])tured. 



Additional interest to this subject has been 

 recently elicited through some charming pa- 

 pers on " Insectivorous plants," by Prof. Asa 

 Gray, detailing many interesting observations 

 and experiments on the structure, habits and 

 functions of Dimicea, Drosera and Sarracenia. 

 But by far the most interesting paper on this 

 subject, in its entomological and physiological 

 bearing, is one recently contributed by Prof. 

 C. V. Riley, of St. Louis, Mo., to the Decem- 

 ber number (1874) of Hardwick^s Science Qossip, 

 on the " Spotted Trumpet-leaf," {Sarracenia 

 variolctris,) which, according to the testimony 

 of the Professor, must henceforth be ranked 

 in comparison with other plants of a similar 

 habit, as' 'a most consummate insect catcherand 

 devourer." It is not thefloiars, but the pecu- 

 liar, although varied, construction of the leaves, 

 which form the traps in which the various 

 kinds of insects that visit these plants are 

 captured. This fact is important, because the 

 leavts are earliest and latest in their appear- 

 ance, endurance and decay, and very probably 

 appropriate this kind of food, "from first to 

 last." The leaf of the Sarracenia — the plant 

 upon which Mr. Riley made his most interest- 

 ing observations— is trumpet-shaped, a gently 

 widening tube, with an arched lid, partially 

 or quite covering the mouth. The inner sur- 

 face of this tube is pubescent, that is, covered 

 with a coat of smooth silky hairs, inclined 

 downward. These, however, only extend about 

 midway between top and bottom, and from 

 thence downward the tube is beset with bris- 

 tles, with their jioints inclining upward, and 

 these increase in size until near the bottom, 

 where they are replaced by a perfectly smooth 

 surface. This receptacle at the bottom of the 

 trumpet-shaped pitcher, secretes a limpid fluid, 

 which possesses intoxicating qualities, and 

 here is where the insects meet their death. 

 Inside the mouth of the pitcher, and on the 

 underside of its pubescent lid, there exude 

 drops of a sweetish viscid fluid ; this, doubt- 

 less, is the fatal decoy. 



The insects most numerously captured are 

 eints, although insects of all the diflerent orders 

 become victims. The decomposition' of the 

 bodies of these ants is supposed to add their 

 acidulous qualities to the secretion of the plant, 

 at the bottom of the tube, and increase its 

 solvent properties. Except auts, it a])pears 

 that but few other Hymenoptera are captured, 

 occasionally a Bombus or an Apis. 



Prof. Riley says he found most commonly, 

 in a recognizable condition, several species of 

 Coleoptera and two or three of Hemiptera; ' 'while 

 katy-dids, locusts, crickets, cockroaches, flies, 

 moths, butterflies, si)iders and centipedes, in a 

 more or less unrecognizable condition, helped to 

 swell the unsavory mass" at the bottom of 

 the pitcher. The natural inference is, that 

 these insects are decayed and macerated in 

 order to support the plant, and the testimony 

 of dift'erent observers goes very far towards prac- 

 tically demonstrating that this is not " only a 

 speculation," but a/oct. 



But although the macerating fluid at the 

 lower end of this pitcher is so fatal to most 

 insects, there is at least one species that has 

 the power of resisting its influence. A large 

 flesh-fly, described by Prof. Riley in the trans- 

 actions of the "St. Louis Academy of Sciences" 

 as Sarcophaya sarracenia, the larva of which 

 feeds upon the putrid insect remains in the 

 tube, and when it is perfectly matured, as a 

 larva, it bores through the leaf just above the 

 stem, escapes through the aperture, and bur- 

 rows into the ground, where it contracts to a 

 pupa, and in due time comes forth a perfect 

 fly, not much unlike the large gray and hairy 

 fly which is attracted by putrid flesh. If it be 

 asked how this insect can resist the action of a 

 fluid so fatal to all other insects, we can only 

 answer that we cannot tell, any more than we 

 can tell why it is that the larva of the bot-fly re- 

 sists the effects of the gastric juice in a horse's 

 stomach, which is capable of digesting oats, 

 hay and corn. 



Perhaps more remarkable still, in resisting 

 the siren influence of the trumpet plant, is a 

 small species of moth (Xanthoptera semi- 

 crocea) or "Sarracenia moth," which walks 

 with perfect impunity over the inner surface 

 of the pitcher, or trumpet, so fatal to other 

 insects. The female lays her eggs near the 

 mouth of the pitcher in April, and as soon as 

 the young larva comes forth from the egg, it 

 spins for itself a smooth silken carpet, and very 

 soon also closes up the mouth by drawing the 

 rims together, and covering them with its web, 

 which, of course, then debars the entriince of 

 any other insect. By the time the laiTa has 

 matured, the lower portion of the tube is filled 

 up with its excretions, and above this mass the 

 pupa is formed in a slight cocoon. As the 

 leaf depredated upon by this moth collapses 

 above where the pupa is located, and finally 

 dies, the escape of the imago is thereby facili- 

 tated or provided for. 



These two insects, Prof. Riley continues, are 

 the only ones of any size that can invade the 

 death-dealing trap with impunity ; but he 

 mentions two other minute species sometimes 

 found crawling within the pitcher; and also a 

 parasite upon the larva of the SarcojAaga, be- 

 longing to the "chalcis-flies, " which must in- 

 sinuate itself with iniijunity, in order to reach 

 its host at the bottom of the pitcher. The 

 reasons for certain insects enjoying an immu- 

 nity from capture and deatli, and certain 

 others falling victims, are explained on the 

 basis of the difEereut structure of the feet ; 

 but as this is not particularly germain to the 

 subject, we omit their details for the present. 

 The fertilization of some plants by insects is 

 well understood and pretty extensively ac- 

 knowledged ; but that certain plants carnivo- 

 rousiy api)ropriate and digest animal food is 

 comparatively new to the masses, although the 

 doctrine was advanced more than a hundred, 

 years ago, or nearly so long ago. 



We have on sundry occasions noticed on 

 the leaves of Drosera rotundifolia in this coun- 

 ty, the feet, wings and thoracic and abdomi- 

 nal scales of flies and other small insects, the 

 moist and fleshy parts having been in some 

 manner evaporated or absorbed by the plants ; 

 and our impression was that they were in some 

 way beneficial to the plant. If a small pebble 

 or bit of wood is thrown upon the leaf, it 

 clo.ses in upon it the same as it does upon a fly; 

 it, however, almost immediately relaxes and 

 casts it out ; b\it if it grasps a fly or other ani- 

 mal matter it remains closed, it is presumed 

 until the animal is absorbed. Contemplating 

 this subject from any stand-point we will, we 



