134 '^^^ DOCTRINE OF DESCENT. 



is of great size, barely separated from the crop, and is 

 capable of inflation. A second group includes Carriers, 

 Runts, and Barbs, which possess in common a long beak, 

 with the skin over the nostrils swollen and often carun- 

 culated or wattled, and the skin round the eyes bare and 

 likewise carunculated. To another group, with shorter 

 beak, and the skin round the eyes only slightly devel- 

 oped, belongs the Fantail, in which the normal number 

 of twelve tail feathers may rise to forty-two with aborted 

 oil-gland; also the Tumbler, in which the beak becomes 

 extremely short, and a sickly disposition of the brain, 

 produced and exaggerated by selection, and manifesting 

 itself by tumbling, has been transmitted for more than 

 250 years, and has become established as the character- 

 istic of a race. In the fourth group, the Trumpeter oc- 

 cupies a prominent position, on account of its peculiar 

 voice; likewise the Laugher, or Indian turtle-dove, com- 

 prising several sub-races scarcely differing in structure 

 from the rock-pigeon (Columba livia). The latter is di- 

 vided into several geographically distinct races, ranging 

 from the coasts of the Faroe Islands and Scotland to 

 the shores of the Mediterranean and to India; and the 

 most minute investigation, whether the incredibly di- 

 vergent races of domestic pigeons are derived from eight 

 or nine wild species or solely from the wide-spread rock 

 pigeon, results decidedly in favour of the latter alterna- 

 tive. Proportional dimensions, colouring, and parts of 

 the skeletons which differ from one another far more 

 widely in the various races than they do in well marked 

 species of the same genus, or even family, are modified 

 under the hand and according to the will of man; and, 

 moreover, pre-eminently in the pigeon may be traced 



