354 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



sition of the animals which they capture by means of their bladders, 

 which constitute genuine traps, acting like mouse- traps when in the 

 air, and like fish-traps when in the water or in a very humid soil. 



As regards other carnivorous plants, nothing is wanting to make the 

 analogy of their digestion with that of animals complete. There is the 

 preparatory act, the capture of the living prey, and the essential act 

 characteiiziug digestion, namely, the dissolution of an acid and of a 

 special juice over food of a proteinous nature; that is, food that among 

 its component parts contains nitrogen. Numerous experiments made 

 by many botanists, especially those made by Francis Darwin,* have 

 clearly shown, in spite of the doubts expressed by other naturalists, 

 that animal matter, absorbed in the manner described, enters directly 

 into the composition of these plants, and is exceedingly useful if not 

 indispensable to their normal development. 



Among the victims commonly found in the traps of carnivorous 

 plants, as far as known till quite recently, there were only insects and 

 small crustaceans. But a short time ago Mr. Simms, of Oxford, brought 

 to Professor Moseleyt a vessel containing a specimen of Utricularia 

 vulgaris (Plate 1), and a number of small Leuciscus rutilus,% recently 

 hatched. Many of these small fish were dead, and were held firmly 

 between the valves of the bladders of this voracious plant. The En- 

 glish professor, beiug interested in this remarkable discovery, procured 

 another specimen of the Utricularia and a supply of eggs and young of 

 the Leuciscus rutilus. Six hours later he noticed that more than a dozen 

 of the young fish had been seized by the plant. In most cases the fish 

 are seized by the head (Plate 2, Fig. 1), and sometimes by the tail (Plate 

 2, Fig. 2). One of the little fish had even been seized by the belly* and 

 another by its two extremities by two bladders at a time (Plate 3, Fig. 3). 

 These last-mentioned facts seem to confirm the opinion of Mrs. Treat 

 that the carnivorous plants seize the animal of their own accord, and 

 from this opinion she draws the conclusion that there actually exists in 

 these plants a characteristic nervous tissue. But numerous experiments 

 made by Charles Darwin with one of these plants, the Drosera, by ap- 

 plying to it acids, alkalies, and alkaloids of various mineral or organic 

 salts, show too great a diversity in their results to allow us to draw 

 therefrom any definite conclusion. Mr. Planchou says with regard to 



* "Insectivorous Plants" in Nature, January 17 and June 6, 1878. Iu the carniv- 

 orous plants, which Darwin subjected to a meat diet, the weight of the non-blooming 

 part attained the proportion of 121, that, of the floral sterns 240, that of the seed 

 grains 380, and of the young plants produced from slips 251, while in other plants it 

 was only 100. 



tBuU. F. C.,vol.iv,p.259. 



JTue Utricularia is a dicotyledonous monopetalous plant, belonging to the family 

 of Utricularia or Lenlibularia. Several varieties of this plant, especially the Utricu- 

 laria vulgaris, U. neglecia, U. minor, &c, are also found in France, and even, though 

 rarely, in the neighborhood of Paris, in ponds iu the woods of Meudon, in the forest 

 of Compiegue, &c. 



