1896] NATURAL SCIENCES OF PHILADELPHIA. 233 



cesses; 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 strength- 

 ens 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 mathe- 

 matical precision. If Dr. Haughton, of Cambridge, can demon- 

 strate the mathematics of the bones and muscles, surely some one 

 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.^" 

 In the same vear he endeavored to establish a dvnamical theorv 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 gigan- 

 tic extinct armadillo. 



He developed a theory on the origin of the amnion in 1 886, and his 

 explanation of the difierent 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 inter- 

 rayomeric fissures."^^ Ryder'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 difierent character, and sustained by broadly contrasted methods 

 of expression. Allusion is made especially to his studies of the con- 

 tractility of protoplasm, which is first mentioned in his paper, " On 

 the Fore and Aft Poles, the Axial Ditferentiation and a Possible 

 Anterior Sensory Apparatus of Yolvox minor" and in his paper on the 

 " Origin and Meaning of Sex." These papers began a series which 

 (included in the bibliography under numbers 174, 186, 190 and 191) 

 dealt not so much with problems in dynamics as with the old vital 

 doctrines, or, as would be expressed in modern phrase, metabolism. 

 " The Origin and Meaning of Sex " appeared in the Biological Bul- 



10 Law of Digital Reduction, Proc. A. X. S., 1877. 

 " E. D. Cope, Memorial Pamphlet. 



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