Azotes and Observations on a Guan. 287 



Other iustances of this purely arboreal stamp and archaic 

 form occur to my mitid^ in the case of certain Neotropical 

 Cuckoos, such as Coccyzus and Sawothera , which live au 

 essentially skulking life in the densest thickets. 



In these purely arboreal features then, -which we have 

 thus briefly referred to, we seem to see represented almost 

 an exact antithesis of what obtains in game-birds which live 

 continuously on the ground ; but if, as some might argue, 

 this complete arboreal equipment has only been developed 

 in an efl:brt to revert to an ancestral mode of life, it seems 

 strange that in the immense lapse of time which must have 

 l)een necessary for its production, the Guan has not, at the 

 same time, been able to completely lift, so to speak, its 

 offspring from the ground to its new home among the 

 trees. 



Whether birds were originally all arljoreal-liviug or all 

 originally terrestrial-living, or even purely aquatic, Avhich 

 seems just as likely, appears as yet to be quite an open 

 question; but that the purely ground-living game-birds of 

 the present day originally led an arboreal existence seems 

 to be a fact beyond dispute. 



If this is so, there must have been stages when the 

 process of descent to the ground was not complete ; and my 

 contention is that in the case of the life-history of the 

 (juan we have such a stage represented in the present day. 



Nesting habits of the Guans. 



Before continuing our argument however, and before 

 proceeding to the description of this interesting young 

 specimen of a Guan, it may be well to bring forward 

 evidence emphasizing the almost entirely arboreal existence 

 which the Guans live (except perhaps for the possibly short 

 period during which their young are living on the ground), 

 and of the fact, of which I think we now have ample 

 evidence, that they do nest in trees. 



To take the nesting-habits first, I will quote the testimony 

 of three observers, which should be sufficient for the purpose. 



In a reference to Or talis rujicauda on the island of 



