CHAI- VI. DIGESTION. Ill 



mo by Prof. Hoffmann. For comparison, squares of 

 the same size as those placed on the leaves were left 

 close by on wet moss. These soon swelled, but re- 

 tained their angles for three days ; after five days 

 they formed rounded, softened masses, but even on the 

 eighth day a trace of gelatine could still be detected. 

 Other squares were immersed in water, and these, 

 though much swollen, retained their angles for six 

 days. Squares of -^ of an inch ( 2*54 mm.), just 

 moistened with water, were placed on two leaves ; and 

 after two or three days nothing was left on them but 

 some acid viscid fluid, which in this and other cases 

 never showed any tendency to regelatinise ; so that 

 the secretion must act on the gelatine differently 

 to what water does, and apparently in the same 

 manner as gastric juice.* Four squares of the same 

 size as before were then soaked for three days in water, 

 and placed on large leaves ; the gelatine was liquefied 

 and rendered acid in two days, but did not excite 

 much inflection. The leaves began to re-expand after 

 four or five days, much viscid fluid being left on their 

 discs, as if but little had been absorbed. One of these 

 leaves, as soon as it re-expanded, caught a small fly, 

 and after 24 hrs. was closely inflected, showing how 

 much more potent than gelatine is the animal matter 

 absorbed from an insect. Some larger pieces of gela- 

 tine, soaked for five days in water, were next placed 

 on three leaves, but these did not become much in- 

 flected until the third day ; nor was the gelatine ' 

 completely liquefied until the fourth day. On this 

 day one leaf began to re-expand ; the second on the 

 fifth ; and third on the sixth. These several facts 



* Dr. Lander Brunton, ' Hand- phys. de la Digestion,' 18(17, p, 

 book for the Phys. Laboratory,' 24'j 

 1873, pp. 477, 487 ; Scliiff, ' Lcyons 



