July 20, 1906.] 



SCIENCE. 



89 



the beginning. I have not attemiDted to de- 

 fend the mutation theory of de Vries, but only 

 to emphasize the fact that, before we criticize 

 it, or lend to it either our dissent or assent, 

 we must first understand it. The ink that was 

 spilled in discussing misinterpretations of 

 Darwinism far exceeds that poured out in re- 

 cording constructive studies in evolution. Let 

 us not make the same mistake and waste of 

 energy in the present case. 



The mutation ' theory ' is still largely a 

 working hypothesis. It is founded almost 

 entirely upon experiment, and can be verified 

 only by the same means. The beauty of it is 

 that it is already reduced to a question of fact. 

 For mere opinion and inference, and a priori 

 impressions and prejudice, and inductions 

 from field studies and comparative morphology 

 there is absolutely no place. If one doubts 

 the facts, let him repeat the experiments of 

 de Vries and MacDougal and others. If he 

 doubts that, they represent a general truth, 

 a fundamental principle in biology, then let 

 him await the fullness of time, for it is by 

 repeated experiment, among a wide range of 

 groups, and hy experiment only, that the gen- 

 eral application must stand or fall. 



And I bespeak also a candid acceptance 

 of the facts, after they are clearly distin- 

 guished from the inferences. The latter are 

 open to debate, but not so the former. And 

 when a careful worker says that he obtained 

 a given form that breeds absolutely true, and 

 which, for reasons fully explained, he calls an 

 ' elementary species,' by means of a certain 

 definite and clearly explained kind of varia- 

 tion which he defines and names ' mutation,' 

 let us not refer to him as ' claiming to ' have 

 done so, or to the mutant as ' seeming to ' • 

 breed true. 



Pregnant with significance as the mutation 

 theory is for the systematic botanist and zool- 

 ogist, its truth can never be established nor 

 disproved by the methods of taxonomy. Com- 

 parative studies may offer worlds of evidence 

 and multitudes of problems to test the hy- 

 pothesis, but experimentation is the only pos- 

 sible means for the final solution. 



How do species originate? A mass of 

 facts suggests that the method is . by the 



natural selection of fluctuating variations, 

 combined with geographical isolation, in- 

 fluence of environment, and other factors. 

 But, after all has been written, the undeniable 

 fact remains that no one has yet ever actually 

 observed the origin of a single species in this 

 way. 



On the other hand, the fact is just as un- 

 deniable that a definite and clearly defined 

 type of variation, called an ' elementary 

 species,' has been actually observed, not once, 

 but often and by many, to arise by a process, 

 equally well defined and definite, and known 

 as ' mutation.' Mutations do furnish material 

 for the operation of natural selection and all 

 other influences that tend to establish a unit 

 group known in taxonomy as a ' species.' 



The case seems perfectly plain that the 

 burden of proof rests with the adherents of 

 fluctuation. 



C. Stuart Gager. 



New York Botanical Garden. 



SPECIAL ARTICLES. 



a new fossil seal from the marine MIOCENE 

 OF THE GREGGlSr COAST REGION. 



In a bulletin recently issued by the Oregon 

 State University, Professor Thomas Condon 

 has given a description of an unusually inter- 

 esting fossil pinniped, which was obtained by 

 him from the Marine Miocene of the Oregon 

 coast. It is, indeed, a happy coincidence that 

 this nestor of Oregon geology should cele- 

 brate his eighty-fourth birthday by so inter- 

 esting and important a discovery. This does 

 not quite equal the record of the great chemist, 

 Chevreul, before the French Academy, it is 

 true, but it is one sujfficiently rare in paleontol- 

 ogy. 



Professor Condon has kindly permitted me 

 to make a careful study of this unique speci- 

 men, and I do not hesitate to pronounce it 

 easily the most important find that has yet 

 been made in this group. As far as I am 

 aware the specimen represents an entirely new 

 and hitherto unknown genus, intermediate in 

 many respects between the sea lions and seals, 

 with perhaps the most pronounced affinities 

 with the latter, and at the same time exliibit- 



