DARWIN AND PALEONTOLOGY 229 



reaches the climax in De Vries' work, where mu- 

 tation is regarded as an exclusive principle, but 

 discontinuity can never be either demonstrated 

 or disproved by paleontology, since this is the 

 most unfavorable of all the biological fields for 

 the recognition of sudden changes of character, 

 through absence of that abundance of synchro- 

 nous and contemporaneous material for com- 

 parison on which alone it is safe to establish the 

 existence of a mutation. Despite this obvious 

 shortcoming of paleontology, it is noteworthy 

 that the saltatory hypothesis has been — ^illogically 

 I believe — fathered by a series of paleontologists, 

 by St. Hilaire in 1830, by Cope, and more re- 

 cently by Dollo and Smith Woodward. It 

 should be borne in mind constantly that wherever 

 a new animal suddenly appears or a new char- 

 acter suddenly arises in a fossil horizon, such ap- 

 pearance may be attributable to the non-discovery 

 of the greater or more minute transitional links 

 with older forms or to the sudden migration of a 

 new type provided with a new organ or organs 

 which have gradually evolved elsewhere. More- 

 over, the doctrine of sudden appearances is di- 

 rectly the reverse of Waagen's law of mutation. 

 The point, however, is that as a sphere of evidence 

 paleontology neither approves nor disproves the 

 law of discontinuity. 



Slow origins demonstrable by paleontology, 

 but not by botany or zoology. Paleontology, on 

 the other hand, affords the most favored field for 



