ON THE NATURE AND BASIS OF HKKKIMTY. IS") 



In a pair of young pouters from gray (\vhitc-barrcd Briinn) pouters, one (8) is 

 gray with dark bans, and in form is apparently very well developed; 16 the other (9) 

 is white, with poorly developed wings, the primaries being imperfectly developed. 17 

 This bird has the "shakes"; that is, it trembles all over and can not control the 

 movements of the head (I have had two such white birds from a dealer, and they 

 are evidently of the same nature). This bird was hatched October 11, 1908, and 

 at the age of 5 to 6 weeks, though of good appetite, was quite unable to fly. 

 This white pouter died January 27, 1909, and turned out to be a female, as \\as its 

 nest-mate, both hatched in October 1908. 



In another case a pair of birds consisting of a male orientalis x risoria hybrid 

 (8) and a female St. alba hatched both eggs of a clutch on June 5, 1908; and again 

 both eggs of another clutch on July 7. They laid again (third time) July 22 and 2 1. 

 when the young from the second clutch were only about 2 weeks old and not yet 

 out of the nest. This set of eggs, produced so early after the preceding eggs, failed 

 to develop. Either this was due to the presence of young in the nest (the latter 

 would prevent steady sitting) or to weakening of the germs (late in season) and to 

 the strength of the old birds being reduced by the care of vigorous young. 



Short abnormal legs. In several crosses between common pigeons (C. livia 

 domesticd) and T. orientalis of Japan, I have had young hatched with legs abnor- 

 mally short, so that in course of a few days, as the body rapidly grew, the legs came 

 more and more to point more or less directly backward, and to be of no use in 

 enabling the bird to reach up for its food. 



So far as memory and some records serve, this condition did not appear in any of 

 the first offspring raised in the better part of the season April to June but in the 

 later offspring of July and August. This deformity may, then, be ascribed to failing 

 or diminished germ-energy. 



This view is confirmed again this season (1909) in a cross between a homer and a 

 hybrid between T. turtur and T. orientalis (TO 8). The products of this cross (up to 

 July 22) are as follows: 



Kirst set of ciiKS, April 12 to 1 i, normal development. 



Second sot of egp.s, April 22 to 24, normal development. 



Third set of CKKS, May 1 to 3, normal development. 



Fourth set of eggs, May Id to IS, normal development. 



Kiftli set of ows. May 28 to 30, normal development. 



Sixth set of onus, July 1 to 3, first, short legs; second, logs normal. 



Note that I have worked these birds abnormally rapidly, and probably that, 

 added to the usual strain, has been sufficient to weaken reproductive power. In the 

 earlier part of season transference of eggs is followed by immediate renewal of 

 the nesting cycle. In the later part of season the birds lose a week or more before 

 renewing their efforts. 



Distorted development, wry neck, <!olic<>ce/)li<il/xi. In 1906 I mated an imported 

 male Japanese turtle with a female hybrid (SO 2) obtained in 1904 from a cross of 

 St. risoria and T. orientalis. The result was one secondary hybrid (tfO-SO 2-E) 

 which was able to live and mature. This bird has thus far proved infertile. He 



1(1 A neat bird but. a degenerate, as shown by color and also by her early failures to produce eggs. 



''Thefeathereof this bird were slow and irregular in growth ;i1 was never able m ily, though it lived 3J months. 

 It was kept in the house and well cared for; no cause of death but weakness. The legs sprawled, so that walking was 

 awkward and difficult; it was shaky like a fantail, and the primaries hung loosely apart . 



