596 MOULT 



here Ave have briefly to consider the difl"erent phases which the act 

 of Moulting offers. 



As a general rule all kinds of Birds are subject to an annual 

 Moult, and this commonly begins immediately on the close of the 

 breeding-season, but, as will be presently explained, there are 

 some which undergo in addition a second or even a third partial 

 change of plumage, and it is possible that there may be others still 

 more exceptional : our information respecting these, however, is too 

 meagre to make it worth while saying anything here about them. 

 It must be acknowledged that with regard to the greatest number 

 of forms we can only judge by analogy, and though it may well be 

 that some interesting deviations from the general rule exist of 

 which Ave are altogether ignorant, yet Avhen we consider that the 

 Pcatitx, so far as observed, moult exactly in the same manner as 

 most other birds,^ the uniformity of the annual change may be 

 almost taken for granted. 



It is not intended here to say more {cf. p. 248) of the Avay in 

 Avhich a feather dies and a new one succeeds it, nor need we com- 

 pare the process of moulting Avith the analogous shedding of the 

 hair in Mammals or of the skin in Reptiles, though the latter, in 

 the case of the flipper-like Avings of the Penguin — the scaly feathers 

 of Avhich come oif in flakes — Mr. Bartlett {Proc. Zool. Soc. 1879, p. 

 6) has shewn to be remarkably close. Enough for our present 

 purpose to see that such renovation is required in Birds, nearly all 

 of Avhich have to depend upon their quills for the means of loco- 

 motion and hence of livelihood. It is easy to understand that dur- 

 able as are the flight-feathers, they do not last for ever, and are 

 beside very subject to accidental breakage, the consequence of 

 which Avould be the crippling of the bird.^ It is obviously to pro- 

 Adde against Avhat in most cases would be such a disaster as this last 

 that we find the remiges, or quill-feathers of the Avings, to be nearly 

 always shed in pairs. They drop out not indeed absolutely at the 

 same moment, though this sometimes seems to happen, but Avithin 

 a few days of each other, and, equilibrium being thus preserved, 

 the poAver of flight is but slightly deteriorated by their temporary 

 loss. The same may be observed in a less degree, since there is 

 less need of regularity, Avith the rest of the plumage, as a little 

 attention to any tame bird Avill shew, and the neAV feathers groAV at 

 an almost equal rate. In the young of most species the original 

 quills are not shed dui'ing the first year, nor in the young of many 

 does there seem to be an entire moult during that time, but in the 



^ For the knowledge of this fact I am indebted to the vast experience of Mr. 

 Bartlett. 



- By an ingenious but simple process known as "imping," which properly 

 means engi-afting, and is described in almost every book on hawking, falconers 

 repair any broken flight-feather, and so restore the bird to its full power. 



