MEMORIAL OF S. W. WILLISTON iO 



general work on the Reptiles of the Wo7dd, Recent and Fossil, on which 

 he was actively engaged up to his last illness ; also the publication of his 

 papers on Edaphosaurus, on the atlas-axis complex of reptiles, and, 

 equally important, his brief paper on the "Phylogeny and classification 

 of reptiles/' previously mentioned. During the last two years of his life 

 he was also preparing a paper on new Permian reptiles. 



In summing up his life-work, "I like/' says Doctor Gregory,'' "to em« 

 phasize the general features in which Williston was really preeminent, 

 namely: (1) Discovery of new material — Cretaceous Eeptilia, Permian 

 Tetrapoda, and Diptera; (2) conscientious and precise description of 

 these ; ( 3 ) eminently conservative synthesis of facts, so as to work out a 

 great and enduring record of Cretaceous and Permian reptiles; (4) in- 

 tensive and successful specialization in several distinct lines of research 

 and teaching." 



It is a matter of the deepest regret to all of Williston's colleagues in 

 paleontology that he did not live to complete his great comparative work 

 on the Eeptilia, which would have summed up all his researches and ob- 

 servations and the facts store d in his mind which have never found their 

 way into print. As an investigator he combined in an exceptional degree 

 anatomic accuracy in detail with breadth of vision and power of analysis. 

 His associates in the special field of Permian research considered his 

 opinion as a homologist weighty. A committee was formed, chiefly com- 

 posed of Americans, of which Williston was senior, to endeavor to estab- 

 lish the difficult and intricate questions of homology and to base on this 

 an enduring terminology to replace the confusing whirlpool of names for 

 certain skull bones which have accumulated since the time of Cuvier. 



A few of the more general features of Williston's life-work and char- 

 acter are as follows : He strove arduously through forty years of investi- 

 gation to discover new material in the field and to widen our basis of 

 facts in several distinct lines of investigation; he preferred to discover 

 new facts rather than to reinterpret older ones or to adjust the interrela- 

 tions of facts; in general, his material was notably of his own finding. 

 Nevertheless, especially in his late years, he labored very successfully to 

 classify and synthetize his material, and with it that which had been 

 treated by other workers. Here his genial personal character and ad- 

 mirable relations with his colleagues shone forth; he was singularly 

 appreciative of the work of other men and ready to adopt whatever he 

 believed to be solid and enduring in previous attempts at classification. 

 Thus Williston's work stands in contrast with that of Cope and Marsh, 

 whose personal differences of opinion led to the setting up of two entirely 



6 See footnote, p. 70. 



