SOME OHSF.HV.VTIONS OS TIIF. MOULTING OP BIRDS. 293 



any material change in their garb, it is inferred that n<> 

 change is necessary; and yet if any notable mutation had ob- 

 tained in any one of the domesticated species, i( is probable 

 it would be affirmed of thai species, that there was some phy- 

 sical necessity for this exception, which did no1 hold of the 

 rest. 



Three great naturalists hive given <>|ii 1 1 i< n 1- on this part of 

 the physiology of Birds, which dom t altogether coincide with 

 each other. From Buffon we learn that they moult but one* 

 a year*. Baron Cuvier says thai their feathers Fall tvria a 

 yearf. And Temminck informs us, that, in some gem ra, the 

 whole of the species are subject to a double change of plu- 

 mage: in others, only some of the species experience it ; whilst 

 in the remainder, the moulting takes place bul oner a war}. 



The object of this inquiry is to ascertain, whether the opi- 

 nion of Temminck. thai some Birdsg change their plumagi 

 Urici a year, is founded in fact. 



The intention of Nature in rem wing the covering of Birds, 

 appears to be a revigoration of those powers which are neces- 

 sary to the propagation and conservation of the animal. At- 

 ter the breeding season is passed, the period of moulting com- 

 mences. The effects of this exhausting process, which, if 

 not a disease) . is closelj allied to it. are well known. When 

 the Bird recovers its strength, we find it in a new garb, which 

 advances to perfection in proportion to its necessities: th< 

 which migrate to great distances standing in need of ;i speed} 



It seems thai Temminck is doubtful whether the female* moult more than once . 

 this doubt baa arisen, we presume, from bis inability to discover any variation 

 their plum 

 * Discours surla Nature d< • Oiseaux. 



R ■!, tome I, i>. - 



I Manuel <!'• hmitholo 



te, that I have referet ofn tttm 



14 La t pour too ■ ■ I d< maladie, i 



deretraite: la pluparl aonl foiblt el tri b - pendant una tool 



trte malai utrespet ucuna ne chantent tant qu'elle dun 



eachent, prennent pen d'ibal uent plus rarement dana ar* 



brcs, ou dans les prairies." — McOtdvyt. 



VOL. III. 4 E 



