CHANGE OF HUE AND FEATURE 323 



cumstances, no bird being known to hibernate, 

 though many, especially Swallows, have had the 

 reputation of doing so. It has been suggested that 

 Petrels, dislodged in winter from their burrows by 

 a fall of rocks, etc., from a cliff, may have accounted 

 for this, and certainly Storm-Petrels could easily be 

 mistaken for Swallows ; and Pliny must have con- 

 founded Shearwaters with Swifts, since he says 

 that however far ships went from land, the Swifts 

 (Abodes) still flew around them, which exactly 

 applies to these Petrels. 



The temperature of the Ratite birds is lower 

 than that of the ordinary types of the class, and 

 in association with this approach to the mammalia 

 it may be noted that these birds are less long-lived 

 than large birds in general, not reaching apparently 

 more than thirty years. 



One peculiarity of birds to which little attention 

 has been paid is the change of colour or form, or 

 both, to be observed in the bare skin of some forms ; 

 it is most conspicuous and best known in the 

 Turkey, in which the caruncle over the beak 

 becomes, as every one has seen, enormously elon- 

 gated and hangs down on the neck, the throat-skin 

 meanwhile becoming loose and pendulous, while 

 the colour of the neck becomes red, with the face 

 bright blue and the crown bluish-white, the ordinary 

 colour of the naked parts being a dull light red or 

 livid. It is interesting to note that in the splendid 

 Honduras Turkey (M. ocellatd), in which the bare 

 parts are normally rich blue with yellow warts, 



