PHYSIOLOGICAL INTEGRATION IN PLANTS. 281 



direct action of the moist earth, must conduce to an increased 

 current of the liquid evaporated from the one and supplied 

 by the other must serve, therefore, to aid the formation of 

 sap-channels in the ways already described; that is must 

 serve to develop the structures through which mutual aid of 

 the parts is given : the additional differentiation tends imme- 

 diately to bring about the additional integration. Con- 

 trariwise, it is obvious that an interdependence such as we 

 see between the secretion of honey and the fertilization of 

 germs, or between the deposit of albumen in the cotyledons 

 of an embryo-plant and the subsequent striking root, is a kind 

 of integration in the actions of the individual or of the 

 species, which no differentiation has a direct tendency to 

 initiate. Hence we must regard the total results as due to a 

 plexus of influences acting simultaneously on the individual 

 and on the species : some chiefly affecting the one and some 

 chiefly affecting the other. 



