iy PREFACE BY THE EDITOR. 



assigned to Professor Wallace Craig, who was able to arrange for publication only 

 a small part of them; these also will be found in Volume III. 



The dominant feature of Professor Whitman's prolonged study of inheritance 

 and evolution lies in its intensive and diversified attack upon the nature of a 

 specific character. As early as 1897 he wrote: 



It is to a comparative and experimental analysis of specific characters that we must 

 look for a knowledge of the phenomena of heredity and variation. 



As Whitman was a contemporary of deVries, who likewise avowed that the 

 study of the origin of species is to be accomplished through a study of specific 

 characters, it is truly remarkable that the results of the two investigators should be 

 so strongly opposed. The reasons for these divergent conclusions may be demon- 

 strated at some time in the future, but something can now be said as to differences 

 in method and material, which certainly have accompanied the two decisions which 

 now seem to stand in strong disagreement. It is clear, for example: 



(1) That deVries worked with much larger numbers of individuals than did 

 Whitman. A corollary of this is — though it may not at first be entirely evident to 

 all — that Whitman was able to and did more closely study and observe the specific 

 characters with which he worked, and for longer periods of time, in the same indi- 

 vidual. The one study was expansive, the other intensive. 



(2) The purity of the greater part of Whitman's breeding material is beyond 

 question. Can the same be said for de Vries's material of chief reliance? 



(3) The phylogenetic relationships of Whitman's most studied species were 

 known and the direction taken by evolution in the past had been ascertained. 

 Does the want of this orientation in de Vries's material at all qualify his results? 



(4) The observations and resultant theory of de Vries nowhere touch or are con- 

 cerned with recapitulation. Whitman finds this to be the central fact of heredity 

 and organic development, and the specific characters most carefully studied by him 

 reveal it abundantly. Does this difference lend weight to the conclusions of the 

 one or of the other? 



Professor Whitman's devotion to the task of mastering a specific character was 

 not limited by the conventions of any particular line of study; it heeded neither 

 time, personal sacrifice, nor the knotty and thorny interpolations which the ensemble 

 of life-processes is continually throwing upon the path of the biologist when he 

 would isolate and examine a particular vital process; and, surely, these latter 

 difficulties especially beset all studies on the origin and establishment of new forms 

 of organisms. But Whitman was ready and eager to attend to each and every 

 intercalated phenomenon, from whatever foreign or extrinsic source, if its analysis 

 and meaning might lead to a better, surer, or closer measure of realities in his 

 own main sphere of study. It thus happens that along the pathway which he has 

 blazed into the central problems of evolution are to be found other landmarks of 

 discovery — some mere sign-posts and some wide and well-done surveys of regions 

 which lead well into the territory of such other and diverse subjects, as instinct, 

 fertility, animal behavior, correlative variation, and the nature of sex. 



