THEORY OF RADICALS AND MORPHOLOGICAL EQUIVALENi - J7 



sought by the animal or forced upon it • gee. ' ope, 1 



in his masterly work on i of the Fittest," and in pamphlets previously 



published, described "ho -" and •■ 1. - equivalent to 



what ni' have called hoin - uuiiici. his 



•■■in all departments t>t' the animal kingdom of exact and im 

 parallelisms Bustainii tion taken rhis eminent authoi 



at length the location ofgrowtb forced ind Bhowa thi> to be 



•ifii t cause "!' modification, thus bringing out clearly and demonstrating 

 a new law of variation. His opinions with regard to "mimetic analogy" in 

 it and interna] characters differs only in bo far as we have preferred to use 

 term morphological equivalence, because we thought it expressed more 

 l> the phenomena of bomoplasy. Be Bays I »uch coin- 



cident - merely the developmental type common to many heterol 



il region.' 1 With regard to the i 

 of habit, we Bhould also refer to Cope's remarks (p 198 . and examples with 

 which hi explains the origin of generic cl unification of the 



I walls in the Batrachia, and the origin of horns among Ruminants, as due 

 nee, concluding that the use of the angles of the parts in 



■ n tin- head) would result in a normal exostosis of a Bimple kind in the 

 or as horn cores in the Ruminantia. Waagen, in his "Jurassic Cephalo] oda 

 ofKutch,"' has made a valuable contribution to the facts in tracing Beveral par- 

 allel series of Lytoceratinaa in India and Centra] Europe. "The most important 

 ill from the in s plained in the present volume are 



first, that in Kachh, in the Bame manner as in Europe, developmental 

 t, which are in part identical witli the European ones; and Becond, that 

 m of the identical npecies in time during the Jurassic ] > « • i i < > • 1 in Kachh 

 ictly the Bame laws a~ have been observed in Europe." 

 • I irallel series i like those mentioned, which would 1"' augmented 



ther groups of Ammonites were as well known as 

 Phylli explanation is, that the changes of form in the oi 



World it upon law* which wen- innate in them an<l had not to 



r circumstances. The lattei truggle for 



linlv influenced th<- production ol 

 tly ; but the fundamental law upon which these influences acted very 

 likely was not the lav ited by Darwin, but the law of develop- 



j of the organisms •■ an offspring varying in a cer- 



tain well defined direction. If this law be true, the time will come when we shall 



lb tolerable certainty, what given form 



. 



» w 



