COLOUR IN BIRDS AND QUADRUPEDS. 221 



feathers, in every species I have examined, and I presume that the Ptar- 

 magin does not form an exception. The only point of difficulty lies 

 in the spring moulting, and in this Captain Cartwright is pretty ex- 

 plicit. He states, with some hesitation, his belief, from an examination 

 of many specimens, that "all the feathers, in spring, drop off." There 

 could have been no difficulty in ascertaining this fact, from the manner 

 in which young feathers are sheathed during the process of moulting. 

 Here, then, we have another well attested proof of a double moult in 

 those species of birds that are subject to a semi-annual change of co- 

 lour. 



Before concluding my remarks on land birds, it may be necessary to 

 state how far I have found my observations to apply, in regard to a 

 second moult in birds in general. I have examined no species in which 

 an individual was not occasionally found, that was not moulting spa- 

 ringly during spring. This may, however, in some species, have been 

 accidental. The Mocking Bird, Blue Bird, Cardinal Grosbeak, Log- 

 gerhead Shrike (Lanius ludovicianus), and some others, I have reason 

 to believe, do not moult to any extent in spring, although a considerable 

 number of feathers drop off, which are not replaced : and yet in many 

 other species of the genera Tardus and Fringilla, even where no very 

 great change of colour occurred, the moult extended to every part of 

 the body ; whilst the Mocking Bird and the Brown Thrush ( Tardus 

 ferrugineus) did not appear to moult. The Solitary Thrush (Tardus 

 minor), which loses nearly all its spots on the breast in spring, seemed, 

 on the 29th of March, to have acquired a full set of young feathers on 

 the breast. 



Although in many species the moult appeared to be complete in 

 other respects, yet in but two species, the Savannah Finch and Swamp 

 Sparrow, did I discover that the scapulars and tail feathers were moulted; 

 these are stronger and firmer, and as far as my observations have gone, 

 seem, in most of the species, to be shed but once a year ; this will not 

 surprise us, when we take into consideration the diversity in the ope- 

 rations of nature in other animals. The horse, for instance, sheds his 

 hair on every part of the body at least once a year, and yet the hairs in 

 the mane and tail continue to grow during the life of the animal. On 

 the other hand, the thinner and lighter hairs of animals, and feathers 



