584 



SCIENCE 



[N. S. Vol. XLVII. No. 1224 



His detection of fish remains in the Ordoviciau 

 rocks of Colorado, again, carried back by a stage 

 the earliest appearance of vertebrates in the suc- 

 cession of life forms. But it is in the Cambrian 

 strata that Dr. Walcott has found chief scope for 

 his labors, which, pursued principally upon the 

 American continent, have often had a V70rld-wide 

 importance. Realizing the dual part which the ex- 

 ponent of paleontology is called upon to sustain, 

 he has illuminated that science alike in its geolog- 

 ical and in its biological aspect. Under the 

 former head should be mentioned the determina- 

 tion and collation of the stratigraphical sequence in 

 numerous districts, and the light thrown thereby 

 upon the problems of paleophysiography. In par- 

 ticular, Dr. Walcott 's study of the geographical 

 distribution of the Cambrian faunas, establishing 

 the existence of two distinct provinces, marked a 

 signal advance in this field. On the biological side 

 his work has been no less fruitful in results. It is 

 sufficient to recall the series of memoirs dealing 

 with the Trilobites, in which he greatly elucidated 

 the organization of that important group, and 

 again his two handsome volumes on the Cambrian 

 Brachiopoda. 



In recent years, with energy which a younger 

 man might envy, he has pushed his researches into 

 the Eocky Mountains of Canada, amidst scenery 

 which his beautiful photographs have made known 

 to many. There he has been rewarded by the 

 bringing to light of two richly fossiliferous hori- 

 zons in the Middle Cambrian succession, including 

 in one an assemblage of fossils marvelous for the 

 perfect preservation of their detailed structure. 

 The preliminary account of the discovery has 

 aroused keen interest, and paleontologists eagerly 

 await the full description by a master hand of 

 this unique collection. 



If by his official status, joined with his personal 

 record. Dr. Walcott is in some sense representative 

 of American geology, with its large opportunities 

 so ardently embraced, the occasion may remind us 

 that community of scientific interests is perhaps 

 not least among the links which unite your coun- 

 try to ours. I have much pleasure, Sir, in placing 

 this medal in your hands for transmission to its 

 recipient, and trust that his future career may in- 

 clude achievements no less brilliant than those 

 which we commemorate to-day. 



In handing the Murchison Medal, awarded 

 to Joseph B. Tyrrell, to the Hon. Sir George 

 Halsey Perley, high commissioner for the Do- 

 minion of Canada, for transmission to the 



recipient, the president addressed him as 

 follows : 



The Murchison Medal has been awarded to Mr. 

 Joseph B. Tyrrell in recognition of the value of his 

 many services to geological science. In the 

 breadth of their scope, in the pioneer element which 

 has so largely entered, in the practical benefits 

 which have often followed, those services may 

 stand as typical of Canada's contribution to geol- 

 ogy- 



During more than thirty years Mr. Tyrrell has 

 been frequently engaged in exploiting wide tracts 

 of the little-kno#n Barren Lands of northern Can- 

 ada, making prolonged journeys of a kind which 

 demands no ordinary resolution and endurance. 

 Besides thus adding largely to geographical 

 knowledge by his own efforts, he has done much 

 to make known the results of earlier explorers in 

 the north. While helping very materially to de- 

 velop the mineral resources of the Dominion, he has 

 at the same time gathered much valuable informa- 

 tion touching the older rooks of the region; and, 

 uniting in his own person the geologist and the 

 prospector, he has often shown by example how 

 science and enterprise may go hand in hand, to the 

 great advantage of both. 



On the side of pure science, however, his most 

 notable researches have been in the domain of 

 glacial geology, where his extensive acquaintance 

 with the country has enabled him to arrive at con- 

 clusions of a large order. Prior to 1894 it was gen- 

 erally held that the ice which once overspread Can- 

 ada, east of the Cordillera with its mountain gla- 

 ciers, • emanated from a single center of dispersal. 

 Mr. Tyrrell first demonstrated the existence and 

 approximate limits of a great ice sheet, which he 

 named the Keewatin, centering in the country west 

 of Hudson Bay and distinct in origin from the 

 Labradorean ice sheet on the east. To these two 

 he subsequently added a third, under the name of 

 the Patrician Glacier, which had its gathering- 

 ground to the south of Hudson Bay. His develop- 

 ment of this thesis, involving a discussion of the 

 relations in time and space of the ice sheets radia- 

 ting from different centers, must rank among the 

 most important contributions to the glacial history 

 of North America. 



In forwarding to Mr. Tyrrell this token of rec- 

 ognition from the council of the Geological Society, 

 I beg. Sir, that you will add to our congratula- 

 tions upon what he has already accomplished our 

 hope that many years of activity still remain to 

 him; and this wish will, I am sure, be echoed by 

 his numerous friends on both sides of the Atlantic. 



