149 



2/8). " Symbasis is the normal evolutionary condition of free 

 and extended interbreeding among the individual members of 

 natural species" (p. 277). 



The above quotations indicate what, in the mind of the author 

 of the hypothesis, is the essential difference between this hy- 

 pothesis and its predecessors. The reader is "duly warned" 

 (p. 295) that "kinetic evolution does not come as an amendment 

 to natural selection," for "selection is not merely inadequate as 

 the cause of evolution ; it is not an evolutionary cause at all, in 

 the concrete physiological sense." 



In harmony with the theory, it is most important to dis- 

 tinguish : 



Heterism — "the diversity of individuals inside the species" 

 (p. 318). 



Evobition — the process of change of type through the assem- 

 blage of variations by inbreeding {symbasis). Symbasis may not 

 cause variation (p. 318), but it is the cause, /^r excellence, of 

 evolution. 



Speciation — "The attainment of differential characters by 

 segregated groups of organisms " (p. 278). " Evolution depends 

 upon symbasis, speciation upon isolation " (p. 278). 



Incidentally, in this connection, it seems pertinent to inquire 

 how, since there is no " law of heredity," * can variations be 

 assembled, since they would not be transmitted from parent to 

 offspring. 



The mere proposal of a theory of evolution, purporting to be 

 diametrically opposed to all preceding theories, and whose 

 acceptance implies the total rejection of the latter as not only 

 inadequate but misleading and fundamentally false, is not only 

 a bold claim, but it at once challenges the closest examination and 

 comparison and the most rigid criticism. 



In a careful reading of the book, one is impressed with the 

 conspicuous absence (with i&w exceptions) of definite citations in 

 referring to the literature dealing with other theories, and of an 

 entire disregard, in some instances, of other work that has a 

 direct bearing upon the theory proposed as new. For example, 



*Cook, O. F., & Swingle, W. T. Evolution of Cellular Structures. Bull. 

 Bureau Plant Industry, 8i : 9. 1905. 



