54 Chapters in Modern Botany CHAP. 



off, and the carcase or refuse then dropped." " A lump of 

 raw meat being thrown to it, in the short space of five 

 minutes the blood will be thoroughly drunk off, and the 

 mass thrown aside. 1 ' " Its voracity is almost beyond be- 

 lief." Just as in this story we find a magnified and dis- 

 torted image of the actual sundew, so in the same way the 

 sober and scientific natural history treatise of Aristotle 

 gradually, though alternately unthinking and fanciful copy- 

 ing, became all but unrecognisably transformed into that 

 marvellous compendium of fabulous natural history, the 

 Physiofagus, whence herald or gargoyle-carver drew his 

 fantastic images. In earlier beginnings we may perhaps 

 detect the same process at work upon more of Darwin's 

 volumes than the one we have been discussing. 



Difficulties. When Darwin published his book on In- 

 sectivorous Plants, there were many who disbelieved on the 

 ground that " only animals have the power of digestion." 

 But Morren and others more definitely soon showed the 

 mistakenness of this opinion, for indeed all plants have 

 digestive ferments, and many have two or three. The 

 peculiarity of the insectivorous plant lies then in the out- 

 pouring of the digestive juice, not in the possession of it. 

 For- even the absorption of organic material is not unique; 

 it is exhibited by the fungi which live among rottenness 

 and by some parasites like the dodder. 



How could this exudation of digestive juice begin? 

 May we begin from glands such as those of some Saxi- 

 frages, Primulas, Geraniums, and suppose with Darwin 

 that the exudation of digestive fluid began with an exos- 

 mose induced by the juices of decaying insects caught 

 among the hairs, and that the habit once set up would be 

 perfected by natural selection? Or may we suppose that 

 the glands and their exuded secretion have always had 

 and still have some meaning, apart altogether from in- 



