No. 6.] HOOKER — CARNIVOROUS HABITS OF PLANTS. 367 



open air for a week, aod placing it in an unopened but fully 

 ibrnied pitcher of iV. Rafflesiana, it was acted upon similarly 

 and very little slower. 



That this process, which is comparable to digestion, is not 

 wholly due to the fluid first secreted by the glands, appears to 

 me most probable ; for I find that very little action takes place 

 in any of the substances placed in the fluid drawn from pitchers, 

 and put in glass tubes ; nor has any followed after six days' im- 

 mersion of cartilage or fibriue in pitchers of N. amjmllaria placed 

 in a cold room ; whilst on transferring the cartilage from the 

 pitcher of iV. ampullaria in the cold room to one of Eafflesiana 

 in the stove, it was immediately acted upon. Comparing the 

 action of fibrine, meat, and cartilage placed in tubes of Nepenthes 

 fluid, with others in tubes of distilled water, I observed that their 

 disintegration is three times more rapid in the fluid ; but this 

 disintegration is wholly difi"erent from that efiected by immersion 

 in the fluid of the pitcher of a living plant. 



In the case of small portions of meat, ^ to 2 grains, all seem 

 to be absorbed ; but with 8 to 10 grains of cartiage it is not so 

 — a certain portion disappears, the rest remains as a transparent 

 jelly, and finally becomes putrid, but not till after many days. 

 Insects appear to be acted upon somewhat differently, for after 

 several days' immersion of a large piece of cartilage I found that 

 a good- sized cockroach, which had followed the cartilage and was 

 drowned for his temerity, in two days became putrid. In re- 

 moving the cockroach the cartilage remained inodorous for many 

 days. In this case no doubt the antiseptic fluid had permeated 

 the tissue of the cartilage, whilst enough did not remain to pene- 

 trate the chitinous hard covering of the insect, which conse- 

 quently decomposed. 



In the case of cartilage placed in fluid taken from the pitcher 

 — it becomes putrid, but not so soon as if placed in distilled 

 water. 



From the above observations it would appear probable that a 

 substance acting as pepsine is given off" from the inner wall of 

 the pitcher, but chiefly after placing animal matter in the acid 

 fluid ; but whether this active agent flows from the glands or 

 from the cellular tissue in which they are imbedded, I have no 

 evidence to show. 



I have here not alluded to the action of these animal matters 

 in the cells of the glands, which is, as has beep observed by Mr, 



