BLOND AND WIIITIO HINO-DOVKS CkOSSKD WITH MOUUMNC-DoVKS, ETC. 129 



BLOND AND WHITE RINGS CROSSED WITH COMMON PIGEONS. 



The presentation of the data for crosses of the ring-doves \\ilh common pigeons 

 may be prefaced by the following statement 3 made in 1898 by the author: 



Dr. Gunther, of London, wrote me that he had succeeded in Retting a few hybrids 

 between the common dove (C. laticauda) and the so-called ring-dove (St. risoria) and that 

 all the young which he obtained were males. He did not succeed in mating the hybinl.- 

 with either of the parent species, and adds that they were so disagreeably noisy that his 

 neighbors did not like to have them around; he therefore felt obliged to put them into 

 the Zoological Garden, where they were kept for about 6 years. When the last one died 

 a year or more ago, Dr. Gunther kindly sent me the skins. These hybrids were obtained 

 from a white fantail male and a female ring-dove, and apparently all had about the same 

 color, approximating somewhat to the ground-color of the rock-pigeon. Gunther mentions 

 no case in which any white appears. 



A word or two may be said as to what there is of interest in the study of these pigeon 

 hybrids. One argument was drawn from hybrids a long time ago, namely, that they exhibit 

 the characters of both parents and therefore disprove the old preformation doctrine of de- 

 velopment. In other words the ovum can not be a preformed pigeon of a distinct species, 

 because fertilization can turn it into something else. That argument has also been used 

 against the more modern idea of preformation, which might perhaps be expressed by 

 pre-organization, not that adult organs are formed or present in the organism, but 

 that the egg has an oriented organization with a head, so to speak, or with a region 

 anticipating the head, and other regions anticipating other parts. It seems to me that 

 in the study of hybrids we have a very excellent means of approaching the question 

 of whether the egg really represents an organization to begin with. I have found a 

 good many facts in embryology which led me to think strongly that the egg is really 

 an oriented organism. I have found some very puzzling facts in my short experience 

 with hybrids of pigeons. 



There have been very diverse opinions offered as to what the hybrid really includes. 

 Some have maintained that the hybrid includes all the characters of both parents. Naudin 4 

 says: "A hybrid is a livirig mosaic work in which the eye can not distinguish the discordant 

 elements, so completely are they intermingled." Darwin states that "it would be per- 

 haps more correct to say that elements of both parents exist in every hybrid in a double 

 developed state, namely, blended together and completely separate." 



A brief extract from Darwin 5 on the possibilities of establishing a new race by crossing 

 is of interest: 



"Until quite lately, cautious and experienced breeders, though not averse to a single infusion 

 of foreign blood, were almost universally convinced that the attempt to establish a new race, inter- 

 mediate between two widely distinct races, was hopeless; they clung with superstitious tenacity to 

 the doctrine of purity of blood, believing it to be the ark in which alone true safety could be found. 

 Nor was this conviction unreasonable; when two distinct races arc crossed, the offspring of the tirst 

 generation are generally nearly uniform in character; but even this sometimes fails to be the case, 

 especially with crossed dogs and fowls, the young of which from the first are sometimes much diver- 

 sified. As cross-bred animals are generally of large size and vigorous, they have been raised in great 

 numbers forimmediate consumption. But for breeding theyare found to be utterly useless ; for though 

 they may be themselves uniform in character, when paired together they yield during many gener- 

 ations offspring astonishingly diversified. The breeder is driven to despair, and concludes that he 

 will never form an intermediate race. But from the cases already given, and from others which 



3 A stenographic report (slightly corrected by the author, mill adapted l>y the editor) of part of a lecture to the 

 Zoological Club, The University of Chicago, March 9, 1898. 



4 Nouvelles Archives du Museum, torn. 1, p. 151. 

 6 Animals and Plants, Vol. II, p. 66. 



