128 



SEXUAL DIMORPHISM 



M re, Xewton 1 describe it as being situated "immediately 

 beyond the proximal end and the pollex, which last would 

 appear to be thrust away by it to some extent." The 



Fig. 11. Bones of the wing of the extinct Solitaire of Rodriguez, Pezophaps solito.rius. 

 A, male ; B, female. From mounted skeletons in the British Museum of Natural 

 History. 



pollex, however, has not been found, and it seems to me 

 rather that the tubercle occupies the very position of the 

 pollex in normal birds. Possibly the pollex had disappeared, 

 or was really included in the formation of the bony tubercle. 



1 Phil. Trans. 1869. 



