Chap. V. 



DESCRIPTION OF BREEDS. 



147 



other pigeons; and in three skeletons there were one or two extra 

 coccygeal vertebrae. I have examined many specimens of various colours 



from different countries, and there was no trace of the oil-gland ; this 

 is a curious case of abortion. 13 The neck is thin and bowed back- 



13 This gland occurs in most birds ; 

 but Nitzsch (in bis ' Pterylographie," 

 18-10, p. 55) states that it is absent in 

 two species of Coluraba, in several 

 species of Psittacus, in some species of 

 Otis, and in most or all birds of the 



Ostrich family. It can hardly be an 

 accidental coincidence that the two 

 species of Columba, which are destitute 

 of an oil-gland, have an unusual number 

 of tail-feathers, namely 16, and in this 

 respect resemble Fantails. 



L 2 



