ii2 CREATIVE EVOLUTION CHAP. 



our opinion, is the kind of definition which befits the 

 sciences of life. There is no manifestation of life 

 which does not contain, in a rudimentary state either 

 latent or potential, the essential characters of most 

 other manifestations. The difference is in the pro 

 portions. But this very difference of proportion will 

 suffice to define the group, if we can establish that it 

 is not accidental, and that the group, as it evolves, 

 tends more and more to emphasize these particular 

 characters. In a word, the group must not be defined by 

 the possession of certain characters^ but by its tendency 

 to emphasize them. From this point of view, taking 

 tendencies rather than states into account, we find 

 that vegetables and animals may be precisely defined 

 and distinguished, and that they correspond to two 

 divergent developments of life. 



This divergence is shown, first, in the method of 

 alimentation. We know that the vegetable derives 

 directly from the air and water and soil the elements 

 necessary to maintain life, especially carbon and 

 nitrogen, which it takes in mineral form. The animal, 

 on the contrary, cannot assimilate these elements 

 unless they have already been fixed for it in organic 

 substances by plants, or by animals which directly 

 or indirectly owe them to plants ; so that ultimately 

 the vegetable nourishes the animal. True, this law 

 allows of many exceptions among vegetables. We do 

 not hesitate to class amongst vegetables the Drosera, 

 the Dionaea, the Pinguicula, which are insectivorous 

 plants. On the other hand, the fungi, which occupy 

 so considerable a place in the vegetable world, feed like 

 animals : whether they are ferments, saprophytes or 

 parasites, it is to already formed organic substances 

 that they owe their nourishment. It is therefore 



