286 



FOWLS. 



Chap. VII. 



In the eight first birds, belonging to distinct breeds, in this table, 

 we see a decided reduction in the weight of the bones of the wing. 



In the Indian Frizzled fowl, which cannot fly, the reduction is 

 carried to the greatest extent, namely, to thirty-three per cent, of 

 their projjer proportional weight. In the next four birds, including 

 the Silk hen, which is incapable of flight, we see that the wings, 

 relatively to the legs, are slightly increased in weight ; but it should 

 be observed that, if in these birds the legs had become from any 

 cause reduced in weight, this would give the false appearance of 

 the wings having increased in relative weight. Now a reduction of 

 this nature has certainly occurred with the Burmese Jumper, in 

 which the legs are abnormally short, and in the two Hamburghs 

 and Silk fowl, the legs, though not short, are formed of remarkably 

 thin and light bones. I make these statements, not judging by 

 mere eyesight, but after having calculated the weights of the leg- 

 bones relatively to those of G. bankiva, according to the only two 

 standards of comparison which I could use, namely, the relative 

 lengths of the head and sternum ; for I do not know the weight of 

 the body in G. bankiva, which would have been a better standard. 

 According to these standards, the leg-bones in these four fowls are 

 in a marked manner far lighter than in any other breed. It may 

 therefore be concluded that in all cases in which the legs have not 

 been through some unknown cause much reduced in weight, the 

 wing-bones have become reduced in weight relatively to the leg- 

 bones, in comparison with those of G. bankiva. And this reduction 

 of weight may, I apprehend, safely be attributed to disuse. 



To make the foregoing table quite satisfactory, it ought to have 

 been shown that in the eight first birds the leg-bones have not actually 

 increased in weight out of due proportion with the rest of the body ; 

 this I cannot show, from not knowing, as already remarked, the 

 weight of the wild Bankiva. 74 I am indeed inclined to suspect that 

 the leg-bones in the Dorking, No. 2 in the table, are proportionally 

 too heavy ; but this bird was a very large one, weighing 7 lb. 2 oz., 

 though very thin. Its leg-bones were more than ten times as heavy 

 as those of the Burmese Jumper ! I tried to ascertain the length 

 both of the leg-bones and wing-bones relatively to other parts of 

 the body and skeleton : but the whole organisation in these birds, 

 which have been so long domesticated, has become so variable, that 



as 100 : 52 ; — in Dorkings as 557 : 248, 

 or as 100 : 44 ; and so on for the 

 other breeds. We thus get the series 

 of 62, 52, 44 for the relative weights 

 of the wing-bones in G. bankiva, 

 Cochins, Dorkings, &c. And now 

 taking 100, instead of 62, for the 

 weight of the wing-bones in G. bankiva, 

 we ge.*, by another rule of three, 8;} 

 as tr ; weight of the wing-bones in 

 Coch ns ; 70 in the Dorkings; and 



so on for the remainder of the third 

 column in the table. 



74 Mr. Blyth (in ' Annals and Mag. 

 of Nat. Hist.,' 2nd series, vol. i., 1848, 

 p. 456) gives 3£ lb. as the weight of 

 a full-grown male G. bankiva; but 

 from what I have seen of the skins 

 and skeletons of various breeds, I 

 cannot believe that my two specimens 

 of G. bankiva could have weighed so 

 much. 



