COLUMBINE. COLUMBA. 225 



These birdfe feed on vegetable substances, some chiefly 

 on soft fruits, others on nuts, seeds of grasses, and other 

 hard fruits, which they swallow entire, some again on the 

 herbaceous parts of plants. They walk with ease, and 

 even celerity ; have a strong, rapid, and protracted flight ; 

 nestle on trees, bushes, rocks, the ground, or in holes, and 

 lay two elliptical, pure white eggs. The young, at first 

 scantily covered with soft down, are fed with substances 

 previously softened in the crop of the parent bird, from 

 whose mouth they receive it by introducing their bill. 



FAMILY XXVIII. COLUMBINE. COLUM- 

 BINE BIRDS, OK PIGEONS. 



There being only the single family of Columbinse in 

 the order Gemitrices, the characters of the family and 

 order are the same. The variations in the form of the 

 wings and tail, as well as other circumstances, give rise 

 to a number of generic distinctions. The four species 

 which occur in Britain belong to the genus Columba. A 

 solitary individual of an American species has also been 

 adduced, belonging to the genus Ectopistes, and as others 

 have been met with on the Continent, it may be admitted. 



GENUS LXXVI. COLUMBA. DOVE. 



Bill rather short, slender, straight, compressed ; upper 

 mandible having at the base two soft, tumid, bare substances, 

 placed over the nostrils, the dorsal line straight for half 

 its length, arcuato-declinate toward the end, the sides con- 

 vex, the tip obtuse and thin-edged ; lower mandible at its 

 base wider than the upper, its crura slender and elastic, the 

 angle long, the dorsal line short and slightly convex, the 

 tip obtuse. Mouth narrow ; tongue sagittate, narrow, taper- 

 ing to a point ; oesophagus immediately dilated, and soon 

 after expanded into a very large double or two-lobed crop, 



P 



