134 TUE DOCTRINE OF DESCENT, 
phagus 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 carunculated 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 developed, 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 characteristic of a race. In the fourth 
group, the Trumpeter occupies a prominent position, on 
account of its peculiar voice; likewise the Laugher, or 
Indian turtle-dove, comprising several sub-races scarcely 
differing in structure from the rock-pigeon (Columba 
livia). The latter is divided into several geographically 
distinct races, ranging from the coasts of the Faroe 
Islands and Scotland to the shores of the Mediter- 
ranean and to India; and the most minute investi- 
gation, whether the incredibly divergent 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 alternative. 
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, more- 
