ii THE PLANT AND THE ANIMAL 123 



or complementary, always preserving an appearance of 

 kinship. While the animal evolved, not without 

 accidents along the way, toward a freer and freer ex 

 penditure of discontinuous energy, the plant perfected 

 rather its system of accumulation without moving. 

 We shall not dwell on this second point. Suffice it to 

 say that the plant must have been greatly benefited, in 

 its turn, by a new division, analogous to that between 

 plants and animals. While the primitive vegetable 

 cell had to fix by itself both its carbon and its nitrogen, 

 it became able almost to give up the second of these 

 two functions as soon as microscopic vegetables came 

 forward which leaned in this direction exclusively, and 

 even specialised diversely in this still complicated busi 

 ness. The microbes that fix the nitrogen of the air and 

 those which convert the ammoniacal compounds into 

 nitrous ones, and these again into nitrates, have, by the 

 same splitting up of a tendency primitively one, rendered 

 to the whole vegetable world the same kind of service as 

 the vegetables in general have rendered to animals. If 

 a special kingdom were to be made for these microscopic 

 vegetables, it might be said that in the microbes of the 

 soil, the vegetables and the animals, we have before us 

 the analysis, carried out by the matter that life found at its 

 disposal on our planet, of all that life contained, at the 

 outset, in a state of reciprocal implication. Is this, 

 properly speaking, a &quot;division of labour&quot; ? These words 

 do not give the exact idea of evolution, such as we con 

 ceive it. Wherever there is division of labour, there is 

 association and also convergence of effort. Now, the evolu 

 tion we are speaking of is never achieved by means of 

 association, but by dissociation ; it never tends toward 

 convergence, but toward divergence of efforts. The 

 harmony between terms that are mutually comple- 



