COSMIC PHILOSOPHY 



the nervous centres which, differently bundled 

 together, make up the cerebrum, the cerebel- 

 lum, the corpora quadrigemina, the medulla ob- 

 longata, the spinal cord, and the sympathetic 

 ganglia, each of which aggregates is extremely 

 heterogeneous in itself. And then there are the 

 innumerable differences entailed by the highly 

 complicated connections established between 

 one nervous centre and another, by the inos- 

 culations of different sets of nerves with each 

 other, and by the circumstance that some nerves 

 are distributed upon muscles, others upon glands, 

 and others upon ganglia. 



These must suffice as examples of differen- 

 tiation. To go on until we had exhausted the 

 series of differentiations which attend the evo- 

 lution of a single individual would be to write 

 the entire history of an organism — and thus 

 to convert our philosophic discussion into a 

 special scientific monograph. That history was 

 long since thoroughly written by Von Baer. 

 Following out the hints furnished by Lin- 

 naeus, K. F. Wolff, Goethe, and Schelling, this 

 illustrious embryologist announced in 1829 his 

 great discovery that the progressive change from 

 homogeneity to heterogeneity is the change 

 in which organic evolution essentially consists. 

 It was this formula which Mr. Spencer began, 

 some twenty years later, to extend into the uni- 

 versal law of evolution. But, far from having 

 228 



