EVOLUTION BY ATROPHY. 



By Jean Demoor, Jean Massart, and Emile 

 Vandervelde. A new volume in the Inter- 

 national Scientific Series. $1.50. 



The purpose of this work is twofold. The authors aim to 

 show, first, that an essential element of the process of evolution 

 as it goes on among plants and animals is the degeneration, 

 decay, or atrophy of organs or parts of organs, at the same 

 time that other parts or organs may and are generally being 

 carried to a higher stage of development, these modifications of 

 structure being attended with corresponding changes of func- 

 tion. The changes that thus take place in the organism, be 

 they upward or downward, degenerative or progressive, are a 

 part of the process of adaptation that is everywhere forced upon 

 the living being by environing conditions. Secondly, they 

 point out that what is true in these respects in the field of life 

 or biology is also true, though perhaps to a less extent, in 

 social phenomena or sociology. Societies, like individual or- 

 ganisms, are ever changing, ever adapting themselves to sur- 

 rounding conditions, and undergoing modification through in- 

 fluences that operate both from within and without. Just as in 

 the case of plants and animals, the resulting social evolution is 

 attended by the phenomena of degeneration or atrophy, insti- 

 tutions and customs that were once in the ascendant declining 

 and giving way to be replaced by more highly specialized forms 

 of activity. In biology the principle of natural selection is 

 believed to play a primary part, while in sociology artificial 

 selection is represented as the dominating agent. The authors 

 bring a strong array of facts to the support of their contention, 

 and present their arguments in a clear and simple style. 



D. APPLETON AND COMPANY, NEW YORK. 



