CHAPTER X. 



VOICE AND INSTINCT IN PIGEON HYBRIDIZATION AND PHYLOGENY.' 



If Professor Whitman had completed his work, he would have produced an 

 extensive treatise on the phylogeny of the pigeon group. All of his studies would 

 have been brought to bear upon the problems of phylogeny. The voices and the 

 behavior of the various species would have been used, like their color-patterns, 

 to throw light on the relationships, derivation and method of origin of pigeon 

 species. To this end, Professor Whitman was interested in discovering similarities 

 and differences of voice, and in learning which elements are homologous in the 

 voices of different species. 



The "Voice" manuscripts unfortunately show no approach towards the final 

 stage of working out a complete phylogeny of the group; but this whole volume 

 on behavior is replete with details of likenesses and differences in species, showing 

 here and there species relationships. Many passages, unused elsewhere, but 

 bearing especially on this problem are here gathered together. A considerable 

 body of data on voice and instinct in hybrids contains facts relevant to the sub- 

 ject of species relationships; these data offer, moreover, a contribution to our 

 knowledge of voice and instinct when these are subjected to hybridization. 



Admittedly fragmentary as is some of the material at hand, it is certainly desir- 

 able to give, in this volume, as much as is possible of the presentable results of the 

 author's studies on the topics indicated under the title of this chapter. It is not 

 practicable to isolate the author's statements on species relationships and present 

 them under the topic placed immediately below in this chapter. The editors have 

 therefore diagrammatically represented the lines of descent in a very condensed 

 form; to these figures little other material is added; the specific statements of the 

 author must be sought in other parts of the chapter and in other chapters. The 

 diagrams will perhaps assist the reader in visualizing those statements. It is 

 thought that these figures, 2 representing as they do the lines of descent of those 

 species most referred to in the present volume, may also prove otherwise helpful to 

 an understanding of some of the statements of this and of other chapters. In 

 their present form these diagrams are indeed largely reconstructions by the editors, 

 but the manuscripts for this and other volumes leave no doubt that they approxi- 

 mate to an accurate representation of the author's conclusions; in most cases, 

 however, the conclusion was not based upon voice and behavior alone, but on 

 other evidence, wholly or in part. The second and third sections of the chapter 

 include data on the modification of voice and instinct in hybrids; these have been 

 divided by us on the basis of closer and wider crosses. In a final section are placed 

 some of the more complete studies on the voice (and behavior) of some pure wild 

 species. 



1 This chapter was compiled and edited by Dr. Wallace Craig and Dr. Oscar Riddle. 



2 In figure 2 the parts A and B were drawn by Wallace Craig, C by Oscar" Riddle. 



Ill 



