234 THE THEORIES OF EVOLUTION 



Another author with a leaning toward Lamarck- 

 ism, Th. Montgomery, lays much stress upon the 

 close relations between the germ cell and the other 

 elements of the body which constitute its environment. 

 The germ cell, he thinks, cannot live or act normally 

 if it is protected against the influence of other cell 

 substances. Its food, water and oxygen come from 

 outside, and everything which constitutes its imme- 

 diate environment has already felt the influence of the 

 soma plasm. The germ plasm is therefore absolutely 

 dependent upon the rest of the organism and, through 

 the medium of the organism, upon the external en- 

 vironment. 



Observations and experiments show that the germ 

 plasm is not a divine entity able to exist regardless of 

 all external influences ; on the contrary, it is intimately 

 bound with the latter. There could not be any deep 

 difference between germ cells and soma cells, for every 

 differentiated cell originates in a germ cell and re- 

 tains a certain quantity of germ plasm ; owing to this 

 similarity in constitution, both necessarily present the 

 same general reactions. 



Thus we observe among modern biologists a tend- 

 ency to find in organic chemistry an explanation for 

 the facts of heredity. While those explanations are 



differences are only chemical differences. While a chemical species can 

 take no primary account of form, chemical similarity usually implies 

 morphological similarity and therefore the individuals constituting a 

 chemical species are similar in form. 



