BIEDS. 



Plate III. 



The heads of Eiiiperoi' Penguins {Aptenodytes forsteri) at various ages. Figs. 1 

 and 2, the heads of chickens in down, at one week and one month respectively ; figs. ^ 

 and 4, of immature birds at five and six months respectively ; figs. 5 and 6, of 

 immature birds at seventeen months. .\11 these are approximately one-third life-size. 

 {See Aves, pp. 20 and 21.) 



