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some degree inherited. True albinism, I imagine, would be 

 the non-development of pigment altogether, such cases as 

 the white stoat in winter and the white mountain hare beins" 

 of a different nature. Or, to take another illustration, a 

 white man is not an albino, though true albinoes, with white 

 hair and pigmentless eyes do occur, both among the white 

 and dark races of mankind. Albinoes in the mammalia and 

 birds are frequent, and I need not specify instances. Among 

 the fishes I have note of white specimens of Rhombus Icevis 

 and Pleuronectes flesus. 



With the mollusca it is by no means unusual to find 

 specimens in which the colouring matter is entirely absent 

 from the shell, and these albinisms are invariably found to- 

 gether, indicating that the peculiarity is transmitted to the 

 young, though coloured specimens have been bred from 

 albino parents. 



The conditions that induce albinism in the shells of 

 mollusca are at present unknown ; albino varieties seem on 

 the whole to be more prevalent on chalky soil than elsewhere ; 

 but here a question arises as to whether all these so-called 

 albinoes are truly so at all. To take a typical instance of 

 what I mean — in Hyalina cellaria the usual form is pale 

 brown — but there is a variety, not very uncommon, in which 

 the shell is pale greenish, while another form has a milk- 

 white shell. Now, many other species have what are called 

 albino varieties, of the milk-white kind, and many others 

 have colourless or pale-coloured semi-transparent ones ; and 

 at first sight it seems not improbable that the transparent 

 forms are the only true albinoes, lacking pigment altogether, 

 and that the opaque white varieties owe their whiteness to 

 some white pigment. Yet, on the whole, I am inclined to 

 class them all as albinisms, and attribute the milk-white 

 appearance merely to a deposit of carbonate of lime. 



In a collection of shells I received some time ago from 

 Kerry, I was much struck by the fact that, although there 

 were specimens both of the coloured and pale or colourless 

 forms of Hyalina excavata, Pupa anglica, and others, all the 

 typical or coloured specimens were from the mainland, while 



H 



