744 



SCIENCE 



[N. S. Vol. XXVI. No. 674 



science, while Chicago, Syracuse and Wis- 

 consin give the master of philosophy, and 

 Chicago the master of letters. The largest 

 number of A.M.'s was given last year by 

 Columbia— 193; Harvard with 152, Tale 

 with 69, and Princeton with 52, being the 

 only other institutions that awarded more 

 than fifty. Chicago, with 54, leads in the 

 number of Ph.D. degrees conferred, and is 

 followed by Columbia, 42 ; Johns Hopkins, 

 35; Harvard, 33; Pennsylvania, 26; Yale, 

 23, and Cornell, 19. 



Illinois leads in the number of degrees 

 conferred upon students of agriculture— 

 43, and is followed by Cornell with 34. 

 New York University granted 32 degrees 

 in commerce. Pennsylvania, with 95, 

 leads in the number of dental degrees, be- 

 ing followed by Northwestern, 88; Michi- 

 gan, 46; Iowa, 38, and Illinois, 34. Chi- 

 cago granted 23 degrees in divinity, Yale 

 11, and Harvard 7, while Yale conferred 

 25 degrees in forestry and Syracuse 14 in 

 music. Columbia leads in the number of 

 bachelor's degrees in education— 103, Mis- 

 souri awarding 42; New York University, 

 37, and Chicago, 21. Northwestern 

 granted 81 degrees in pharmacy; Illinois, 

 30; Michigan, 28, and California, 27; Co- 

 lumbia only gave 12, but to this number 

 should be added the 110 given by the New 

 York college of pharmacy. The largest 

 number of diplomas (not degrees), namely 

 219, was conferred by Columbia University 

 to students of the Teachers College. 



Rudolf Tombo, Jr., 



Registrar 

 Columbia '.University 



EVOLUTION AS IT APPEARS TO THE 

 PALEONTOLOGIST ' 



I DESIRE to introduce this paper by the 

 statement of a law which seems to be axiom- 

 atic, although it is largely ignored by biol- 



' Address before the Seventh International Zool- 

 ogical Congress, Section of Paleozoology. 



ogists. I may term it the law of the four 

 inseparable factors. 



These four factors in the life of or- 

 ganisms are known to us under the terms 

 heredity, ontogeny, environment and selec- 

 tion. The following statement regarding 

 these factors expresses the whole truth: 



1. The life and the evolution of organ- 

 isms invariably center around processes 

 which, in our observations, are grouped 

 under heredity, ontogeny, environment and 

 selection. 



2. These have been inseparable and inter- 

 acting from the beginning. 



3. A change introduced through any one 

 of these factors causes a change in all. 



This I believe to be the most fundamental 

 law of biology ; far more fundamental than 

 the well-known biogenetic law. Yet a sur- 

 vey of recent discussion among biologists as 

 to the theory of evolution shows broad lines 

 of division into several schools of opinion 

 strictly according to the factor from which 

 the subject has been approached. It is true 

 that, conceiving any one of these principal 

 factors as separable, we become involved 

 in endless difficulties; conceiving them as 

 inseparable and continuously interacting 

 under natural conditions, we reach the only 

 true conception of the evolution process. 

 Of these four factors selection is the only 

 one which can be experimentally removed 

 through the agency of man; heredity, on- 

 togeny and environment may be modified 

 but they can not be removed. 



I shall not stop here to demonstrate, as 

 I shall do elsewhere, that changes may be 

 initiated or find a gateway through any one 

 of these four factors ; I shall state simply 

 that imder certain circumstances heredity, 

 under other circumstances ontogeny, under 

 still others environment, or finally under 

 selection, a new order of adjustments be- 

 gins in animals and plants and a new series 

 of characters appears. When such a new 

 Order sets in through any one of these 



