THE INDIVroUAL AND THE SPECIES 171 



Reintegration proceeds all the time. Blastula 

 and gastrula larvae are really organisms capable of 

 leading an independent existence— that is, they are 

 autonomous entities or individuals. The activities 

 of the parts of which they are composed — ectodermal 

 locomotory cells, ectodermal sensory cells, endodermal 

 assimilatory cells, and so on, must be co-ordinated. 

 The cells are in organic material continuity with 

 each other, and events which occur in any one of them 

 affect all the rest. Impressions made upon the 

 sensory cells are transmitted to the locomotory cells, 

 and food-material assimilated by the assimilatory 

 cells is distributed to all the others. At all stages the 

 growing embryo is an organic unity. The more fully 

 it is developed, the greater the morphological com- 

 plexity of the organism, and the more numerous its 

 activities, the greater is the differentiation ; but the 

 greater also is the co-ordination of the organs and 

 tissues. In the higher animals this co-ordination and 

 integration of activities is effected (mainly) by the 

 central and peripheral nervous systems, but specially 

 differentiated nervous cells are not necessary for this 

 purpose. Differentiation during growth is therefore 

 necessarily accompanied by reintegration of the parts 

 dissociated and different iated.^ 



In the process of organic growth the relation 

 between mass and form no longer holds in all the 



^ Societies and civilisations, the associations of bees and ants, or the 

 Modern State, obviously exhibit this differentiation. It is morphological 

 and functional in the case of the Arthropods, since individuals performing 

 difierent duties are modified in form. It is functional only in the case of human 

 societies. Integration of the activities of the individuals in both kinds of 

 societies is effected by inter-communication : articulate symbols in the case 

 of the lower animals, language in the case of man. If the concept of " orders 

 of individuahty " were anything more than a convenient, though artificial, 

 analysis of naturally integral entities, we might speak of the ideal state or the 

 insect society as a " fourth order of individuality." 



