92 DROSERA ROT UNDI FOLIA. [CnAP. VI. 



is manifest that the phosphate of lime is a most powerful 

 stimulant. Even small doses are more or less poisonous, 

 probably on the same principle that raw meat and other nu- 

 tritious substances, given in excess, kill the leaves. Hence 

 the conclusion, that the long-continued inflection of the 

 tentacles over fragments of bone, enamel and dentine, is 

 caused by the presence of phosphate of lime, and not of any 

 included animal matter, is no doubt correct. 



Oelatine. I used pure gelatine in thin sheets given me 

 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 retained 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 gelatine, soaked for 

 five days in water, were next placed on three leaves, but 

 these did not become much inflected 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 prove 

 that gelatine is far from acting energetically on Drosera. 



" Dr. Lander Brmiton, ' Ilnnd- phys. <1p la Digestion,' 1867, torn, 

 book for the I'hj-H. I^Jwmtory,' U. p. 249. 

 1878. pp.477. 487: Srblfr, 'Levona 



