G82 BIOGRAPHICAL SKETCH OF JOHN ADAM RYDER. 



of evolution. That these attempts should have been largely in the 

 direction of dynamics was to be expected, since he was enabled to apply 

 to the problems his talent for mechanics and invention. He also had 

 at hand the conclusions of many contemporaries who were with him 

 eagerly seeking for a hypothesis of evolution not embraced in that of 

 natural selection. 



As early as 1874 he wrote : 



I think I have discovered a law which offers a way to the solution of 

 the variations of forms in animal life. This law I propose to call the law of 

 the dynamics of phylogeny. In reading over Herbert Spencer's brilliant 

 essay on Ihe circulation of sap in plants and the formation of wood, I 

 saw the solution of the problem. Here is field enough for a Darwin. 

 I almost shrink from the task when I consider its magnitude. Cleavage 

 of muscular fiber ; the i)rocesses of bone ; the arrangement of the 

 bony layers ; the change of form and length and of position of bony 

 processes ; their relations as a whole ; their relations to the muscles ; 

 their form, arrangements, etc., all proclaim a common law, while every 

 abnormality, injury, reparative expedient, still further strengthens it in 

 my mind, and is the only thing that will demonstrate to the world the 

 truths of the doctrines of unity of law and universal evolution. It 

 completes Darwin's work on a grander scale than Darwin ever dreamed 

 of. It still further declares that there is one eternal ever-active cause, 

 operating in lines of constant and mathematical precision. If Dr. 

 Haughton, of Cambridge, can demonstrate the mathematics of the 

 bones and muscles, surely someone else can study the dynamics that 

 creates them. 



His first work in speculative biology was an attempt to explain by 

 such reasoning a law of reduction of digits in the mammalia. 1 In the 

 same year he endeavored to establish a dynamical theory to account 

 for the modifications in the forms of tooth structure and to correlate 

 this structure with the shapes of the lower jaw and other parts of the 

 skull. In the following year he discussed the mechanical genesis, 

 degeneration, and coalescence of vertebral centra in a gigantic extinct 

 armadillo. 



He developed a theory on the origin of the amnion in 188G, and his 

 explanation of the different types of placentae in 1887. In 1889 he 

 defended the thesis "that the segmentation of the soft rays of the fins 

 of fishes are simply fractures due to flexures, and that on the caudal 

 fin they possess probably the same direction as the intermyomeric fis- 

 sures." 2 Eyder's bibliography contains fourteen titles of papers which 

 illustrate similar lines of reasoning. 



In the same year we have evidence of additions to his methods, for, 

 while keeping to the lines already indicated, he added others of a differ- 

 ent character, and sustained by broadly contrasted methods of expres- 

 sion. Allusion is made especially to his studies of the contractility of 

 protoplasm, which is first mentioned in his paper on "The fore and 



1 Law of Digital Reduction, Proc. A. N. S., 1877. 

 "E. D. Cope, Memorial pamphlet. 



