248 



M. R. IRWIN 



interaction of the causative genes. This question cannot be completely an- 

 swered until either a genetic separation has been observed, as between the 

 dx-A and d-11, or the chemical separation into two distinct substances has 

 been done. On the other hand, the dx-B fraction has been separated from 

 each of the species specific characters to which it presumably is loosely 

 linked, thereby showing that this fraction of the hybrid substance is an 

 antigenic entity. 



The reagent which interacts with the hybrid substance (hybrid antiserum 



TABLE 15.3 



TESTS FOR SIMILARITIES AND DIFFERENCES OF THE COM- 

 PONENTS OF THE "HYBRID SUBSTANCE" OF THE SPECIES 

 HYBRID BETWEEN PEARLNECK AND RING DOVE 



Symbols: -f -f = marked agglutination; -|- = agglutination; ± = definite but weak agglutination; ? 

 doubtful reaction; = no agglutination — at the first dilution of the serum cell mixture. 



absorbed by the cells of both Pearlneck and Ring dove) will also agglutinate 

 the cells of various species. Thus in the genus Streptopelia, there were five 

 species {capicola, dussutnieri, kumilis, orientalis, and senegalensis) other than 

 Pearlneck and Ring dove whose cells were reactive, and one {semitorquata) 

 with nonreactive cells. Within the genus Columba, the cells of one species 

 (rufina) likewise reacted with this reagent, but those of seven other species 

 (fasciala,flavirostris, guinea, livia, maculosa, palumbus, and picazura) did not. 

 And of twelve species tested in other genera within the Columbidae, only 

 three species from Australia (Australian crested dove, or Ocyphaps lopkofes, 

 the bronze wing dove or Phaps chalcopiera, and the brush bronze wing dove, 

 or Phaps elegans) possessed reactive cells. In Table 15.3, the Senegal cells are 

 representative of the parallel reactions of the five species of the Streptopelia, 



