174 



DOMESTIC PIGEONS. 



Chap. V. 



greyhound with the head of a bulldog, would be a monstrous production. 

 As fancy pigeons are generally kept in small aviaries, and are abundantly 

 supplied with food, they must walk about much less than the wild rock- 

 pigeon ; and it may be admitted as highly probable that the reduction 

 in the size of the feet in the twenty-two birds in the first table has been 

 caused by disuse, 38 and that this reduction has acted by correlation on the 

 beaks of the great majority of the birds in Table I. When, on the other hand, 

 the beak has been much elongated by the continued selection of successive 

 slight increments of length, the feet by correlation have likewise become 

 much elongated in comparison with those of the wild rock- pigeon, notwith- 

 standing their lessened use. 



As I had taken measures from the end of the middle toe to the heel 

 of the tarsus in the rock-pigeon and in the above thirty-six birds, I have 

 made calculations analogous with those above given, and the result is the 

 same,— namely, that in the short-beaked breeds, with equally few excep- 

 tions as in the former case, the middle toe conjointly with the tarsus has 

 decreased in length ; whereas in the long-beaked breeds it has increased in 

 length, though not quite so uniformly as in the former case, for the leg in 

 some varieties of the runt varies much in length. 



As fancy pigeons are generally confined in aviaries of moderate size, and 

 as even when not confined they do not search for their own food, they must 

 during many generations have used their wings incomparably less than the 

 wild rock-pigeon. Hence it seemed to me probable that all the parts of 

 the skeleton subservient to flight would be found to be reduced in size. 

 With respect to the sternum, I have carefully measured its extreme length 

 in twelve birds of different breeds, and in two wild rock-pigeons from the 

 Shetland Islands. For the proportional comparison I have tried with all 

 twelve birds three standards of measurement, namely, the length from the 

 base of the beak to the oil-gland, to the end of the tail, and from the 

 extreme tip to tip of wings. The result has been in each case nearly the 

 same, the sternum being invariably found to be shorter than in the wild 

 rock-pigeon. I will give only a single table, as calculated by the standard 

 from the base of the beak to the oil-gland ; for the result in this case is 

 nearly the mean between the results obtained by the two other standards. 



Length of Sternum. 



Name of Breed. 



Actual 

 Length. 

 Inches. 



Too 

 Short by 



Wild Eock-pigeon . . 2 • 55 



Pied Scanderoon . . 2 • 80 



Bagadotten Carrier 2 " 80 



Dragon 2 -45 



Carrier 2*75 



Short-faced Tumbler 



60 



17 

 41 

 35 



2-05 i 0-28 



Name of Breed. 



Barb 



Nun 



German Pouter 



Jacobin 



English Frill-back 

 Swallow 



Actual 

 Length. 

 Inches. 



Short by 



2-35 

 2-27 

 2-36 

 2-33 

 2-40 

 2-45 



0-34 

 0-15 

 0-54 

 0-22 

 0-43 

 0-17 



38 In an analogous, but converse, 

 manner, certain natural groups of 

 the Columbidse, from being more ter- 

 restrial in their habits than other allied 



groups, have larger feet. See Prince 

 Bonaparte's * Coup-d'ceil sur l'Ordre des 

 Pip/eons.' 



