ALPHEUS HYATT. 44i 



contribution to philosophical ontogeny was his 'Theory of Cellular. tis- 

 sues' which appeared in 1885. The group upon which most of his labor 

 was spent and in the discussion of which he was recognized as facile 

 princeps, is that of the tetrabranchiate cephalopods, popularly known 

 as ammonites, which in early geological ages attained such a marvelous 

 development. More than in many other mollusks the organization of 

 the ammonite is reflected in the characters of the shell and the infancv, 

 maturity and decline of the group to which it belongs is, to the qualified 

 student, pictured in the characteristics of the successive portions of the 

 lustrous coil of the fossil shell. By removing successive portions of 

 these involving symmetrical whorls, the characters of the animal, from 

 the larval stages to senile decay, may be unfolded. Hyatt's researches 

 among these animals set the pace for the most eminent students of the 

 group throughout the scientific world, and his most important publica- 

 tions were devoted to them. With an audience of perhaps a dozen 

 living men who were fully qualified to appreciate the minutiae of his 

 studies, it was not likely that their value could be popularly estimated. 

 But the principles worked out were of far-reaching importance for the 

 students of evolution everywhere, and will bear fruit in the future. A 

 series of similar evolutionary studies of the land shells of the Hawaiian 

 Islands was nearly completed at the time of his death. 



Hyatt's studies of evolution, in geologic time, as well as on existing 

 animals, led him to what are sometimes called Neo-Lamarckian con- 

 clusions. He believed in the hereditary transmission of acquired char- 

 acters, and, in one case at least, proved their transmission. In com- 

 mon with Cope and the majority of American zoologists who have not 

 derived their prepossessions from exotic teachers, he pursued the ideas 

 of Lamarck and Darwin to their logical conclusion, as revealed in the 

 genetic history of the animals he studied, and added to them a body of 

 evolutionary philosophy with which all schools will have to reckon. 



Leaving a subject which verges on the present conflict of scien- 

 tific theories, it remains to say a few words, all too inadequate, on the 

 man whom we have lost. No one who had the privilege of Hyatt's 

 acquaintance but will' join in testimony to his high-minded scientific 

 integrity; the infectiousness of his hearty enthusiasm; the fertility of 

 his imagination, which yet was always controlled by constant reference 

 to experience and observation ; and the general atmosphere of good fel- 

 lowship which he diffused. Unpretentious, open-minded, a constant 

 example of clean living, high thinking, and unassuming kindness to 

 all about him, an ideal husband and father, a steadfast friend ; we shall 

 not soon look upon his like again. 



Professor Hyatt leaves a widow, a son and two daughters, whom 

 the sympathy of his colaborers in two hemispheres may in some slight 

 degree sustain under the consciousness of their common loss. 



