Notes and Ohservations on a Guan. 285 



For Ml)ile^ on the one hand, the parents of the tree-bred 

 young, instanced by Mr. Pycraft, differ as regards their 

 external appearanee and habits in no waij J'roni their more 

 orthodox or normal terrestrial or aquatic relations, tlie parents 

 of tlie tree-bred Guans present, on the other hand, not the 

 sh'ghtest indication (suggested by structure, or general out- 

 ward appearance) of ti;eir ever having led anything but an 

 arboreal life; so that in this respect (as also in tlieir tree- 

 nesting habits, to which I shall j)resently refer) they wouhl 

 seem to form a group apart from all other gallinaceous 

 l)ii-(ls. 



I'hus the absence of spurs ^ and the low position of the 

 hind toe or hallux in relation to the other toes seem both to 

 be features pointing away from a former terrestrial life. 



Again, the unieoloured and neutral tints which charac- 

 terize the plumage of the Guans, in marked contrast to the 

 generally variegated and patterned plumage of the purely 

 ground-living game-birds, seem by reason of their harmony 

 with the sombre shades of the trees to point to a long- 

 continued arboreal life, or, at any i-ate, do not bear witness 

 to a recent terrestrial f one. Both conditions of plumage 

 are, of course, protective, but are protectively adapted to 

 totally different kinds of environments, and between them 

 we could hardly wish for a more striking contrast. 



Moreover, the adult Guan in its ger.eral outward form 

 and shape seems to present characteristics suggestive of a 

 prolonged at;d purely arboreal existence, hardly less pro- 

 nounced than in the case of the Hoatzin. By this arboreal 

 stauip or impress I refer to the small, rather pointed, and 

 Pheasant-like head, the long blunt-ended tail (adapted for 

 balancing), the thin and rather long neck, the very at- 

 tenuated and laterally compressed body (quite unlike the 

 rounded body of ground-living game-birds, and especially 



* By this I do not mean to imply that all terrestrial game-birds have 

 spurs, for we know that some have not. 



t In making- this statement I am aware of the peculiar fact that tlie 

 Megapode by virtue of its neutral and unieoloured plumage is an 

 exception. 



