Chap. XIV. CONCLUDING REMARKS. 331 



the infolded margins apparently serve to absorb de- 

 cayed animal matter in the same manner as the quad- 

 rifids. We can thus understand the meaning of the 

 infolded margins of the lobes furnished with delicate 

 points directed inwards, and of the broad, flat, outer 

 portions, bearing quadrifid processes ; for these sur- 

 faces must be liable to be irrigated by foul water 

 flowing from the concavity of the leaf when it con- 

 tains dead animals. This would follow from various 

 causes, — from the gradual contraction of the concavity, 

 — from fluid in excess being secreted, — and from the 

 generation of bubbles of air. More observations are 

 requisite on this head ; but if this view is correct, we 

 have the remarkable case of different parts of the 

 same leaf serving for very different purposes — one 

 part for true digestion, and another for the absorption 

 of decayed animal matter. We can thus also under- 

 stand how, by the gradual loss of either power, a plant 

 might be gradually adapted for the one function to 

 the exclusion of the other ; and it will hereafter be 

 shown that two genera, namely Pinguicula and Utri- 

 cularia, belonging to the same family, have been 

 adapted for these two different functions. 



