131 Transactions. — Zoology. 



In Mr. Bethune's two specimens now exhibited the wing 

 measures, from the flexure, exactly ll-75in. ; in my inter- 

 mediate example it measures 12in., and in the more matured 

 one only 105in. In the two entirely dark birds the wing, as 

 in the first-named, measures ll-75in. The dark birds have 

 brownish-black legs and feet, whereas in all the others the 

 tarsi are yellowish, and the toes "sandalled" with black; 

 but this difference is no doubt due to the immaturity of the 

 former. 



Art. IX. — Some Curiosities of Bird-life. 



By Sir Walter L. Buller, K.C.M.G., D.Sc, F.B.S. 



[Read before the Wellington Philosophical Society, 19th September, 



1894.] 



Pursuant to the title of my paper, I shall exhibit to you this 

 evening some remarkable " freaks of nature," or curiosities of 

 bird-life. One of them, as I shall presently show, is a pure 

 albino Kiwi, of the small species known to us as Apteryx 

 oweni, the ordinary plumage of which is of a speckled or 

 dappled-grey colour. But before proceeding to the specimens 

 I wish to say a word or two on the subject of albinism. 



The inherent tendency to albinism is one of the distin- 

 guishing features of the New Zealand avifauna. Albinism in 

 the human subject is due to the absence of the minute par- 

 ticles of colouring-matter in the epidermis or outer cuticle, 

 the presence of which, in more or less abundance, gives colour 

 to the skin. In many species of quadrupeds, birds, and 

 reptiles, albinism, due to a precisely similar cause, often 

 exhibits itself, the skin, hair, feathers, and also the hard 

 tissues — even the horny sheaths and scaly coverings — pre- 

 senting an abnormal whiteness. Sometimes, as in the case of 

 white rats, mice, and rabbits, this is accompanied by an 

 abnormal condition of the eyes, which become blood-red. The 

 whiteness of plumage, the purity of which is regulated by the 

 entire or only partial absence of the colouring pigment in the 

 feathers, is thus easily accounted for ; but I have been unable 

 to discover any sufficient reason for the frequency of this con- 

 dition of plumage among the birds of New Zealand._ It is 

 certainly not the result of disease, or of a low state of vitality, 

 any more than albinism in the human subject can be taken to 

 indicate an enfeebled condition of mind or body. May it not, 

 then, be in some way dependent on climatal conditions ? It 

 is significant that in tropical India the tendency is in an 



