JOURNAL OF CONCHOLOGY. 3 
MOLLUSCAN ALBINISM AND THE TENDENCY 
TO THE PHENOMENON IN _ 1893. 
IB IK, ISTUIRIES IONS, fONIES. 
(Read before the Conchological Society, August 22nd, 1894 ; and before 
the Manchester Branch, April 12th, 1894). 
THE object of this little paper is not to set forth a lengthy 
dissertation on Albinism, but by bringing forward a few ele- 
mentary facts and observations, and by an attempt to draw 
deductions from them, to awaken an intelligent interest and to 
call forth further investigation in this much-neglected branch of 
the study of conchology. 
I think it is advisable in the first instance, before dealing 
specially with albinism in the mollusca, to define and give a 
slight sketch of albinism generally. Albinism is lack of colour. 
That Albinism is not due to a white pigment, as occasion- 
ally advanced, is easily proved. The eye of an albino is 
proverbially pink; the pink colour is due to the fact that the 
blood-vessels are visible through the transparent iris. Were 
any white pigment present, such vessels would be obscured by 
it, and the eye would appear white. Albinism is always an 
abnormality. 
There are, it is true, many albino species—instance the 
white rabbit, rat, and mouse; but these are the propagation of 
an abnormality by man, and not natural products. ‘There are, 
also, numerous instances of white animals, such as the polar 
bear, and many birds. These are not albinos. The polar 
bear, although its fur is white, has brown eyes, whilst the 
mucous membrane lining the inside of the lips, and the claws are 
black. Some animals there are, moreover, which are white at one 
season of the year and brown at another. The Alpine hare and 
the ptarmigan are white in winter and brown in summer. 
The above remarks have their bearing on the conchological 
aspect of the subject, as I shall endeavour to show later on, 
