450 The Doctrine of Evolution. 



governmental functions, a series of changes in the relations 

 of the individual to the community. To see so much as 

 this is to whet one's craving for enlarged resources where- 

 with to study human progress. Mr. Spencer had a wide 

 general acquaintance with botany, zoology, and allied studies. 

 The question naturally occurred to him, Where do we find 

 the process of development most completely exemplified 

 from beginning to end, so that we can follow and exhaust- 

 ively describe its consecutive phases? Obviously in the 

 development of the ovum. There and only there do we get 

 the whole process under our eyes from the first segmenta- 

 tion of the yolk to the death of the matured individual. In 

 other groups of phenomena we can only see a small part of 

 what is going on ; they are too vast for us, as in astronomy, 

 or too complicated, as in sociology. Elsewhere our evidences 

 of development are more or less piecemeal and scattered, but 

 in embryology we do get, at any rate, a connected story. 



So Mr. Spencer took up Von Baer's problem and carried 

 the solution of it much further than the great German 

 naturalist. He showed that in the development of the 

 ovum the change from homogeneity to heterogeneity is 

 accompanied by a change from indefiniteness to definiteness ; 

 there are segregations of similarly differentiated units result- 

 ing in the formation of definite organs. He further showed 

 that there is a parallel and equally important change from 

 incoherence to coherence ; along with the division of labor 

 among the units there is an organization of labor ; at first 

 among the homogeneous units there is no subordination to 

 subtract one would not alter the general aspect ; but at last 

 among the heterogeneous organs there is such subordination 

 and interdependence that to subtract any one is liable to 

 undo the whole process and destroy the organism. In other 

 words, integration is as much a feature of development as 

 differentiation ; the change is not simply from a structure- 

 less whole into parts, but it is from a structureless whole 

 into an organized whole with a consensus of different func- 

 tions and that is what we call an organism. So where 

 Von Baer said that the evolution of the chick is a change 

 from homogeneity to heterogeneity through successive dif- 

 ferentiations, Mr. Spencer said that the evolution of the 

 chick is a continuous change from indefinite incoherent 

 homogeneity to definite coherent heterogeneity through 

 successive differentiations and integrations. 



But Mr. Spencer had now done something more than 



