( '9 ) '63 



salamander at that time, because, among other things, 

 the skeleton is represented by cartilage only, and the 

 salamander's is ossified. This relation is therefore an 

 imitation only, and is called inexact parallelism. 



As we compare nearer and nearer relations /. <?., the 

 genera which present fewest points of difference we 

 find the differences between undeveloped stages of the 

 higher and permanent conditions of the lower to grow 

 fewer and fewer, until we find numerous instances where 

 the lower genus is exactly the same as the undeveloped 

 stage of the higher. This relation is called that of 

 exact parallelism. 



It must now be remembered that the permanence of 

 a character is what ,gives it its value in defining genus, 

 order, etc., in the eyes of the systematist. So long as 

 the condition is permanent no transition can be seen : 

 there is therefore no development. If the condition is 

 transitional, it defines nothing, and nothing is devel- 

 oped ; at least, so says the anti-developmentalist. It is 

 the old story of the settler and the Indian : " Will you 

 take owl and I take turkey, or I take turkey and you 

 owl r 



If we find a relation of exact parallelism to exist be- 

 tween two sets of species in the condition of a certain 

 organ, and the difference so expressed the only one 

 which distinguishes them as sets from each other if 

 that condition is always the same in each set we call 

 them two genera : if in any species the condition is va- 

 riable at maturity, or sometimes the undeveloped con- 

 dition of the part is persistent and sometimes transitory, 

 the sets characterized by this difference must be united 

 by the systematist, and the whole is called a single 

 genus. 



