336 DR GEORGE WILSON ON THE 
third generation, that the majority of the parents were albinoes; or that in any 
case all the children of a single pair in an albino line exhibited albinism. 
The human albinoes, accordingly, to whom our physiologists have referred, 
have been generally exceptional or transitional examples of albinism. They 
have inherited the highly sensitive retina, and rapidly contractile, irritable iris 
of their parents, without a similar legacy of the defensive dark pigment, which 
in them protected both organs from the painful impression of excessive light. 
With the instincts, accordingly, of their progenitors, and trained by them to pur- 
suits like their own, albinoes of our own race have sought to follow all legitimate 
callings, and in so doing have soon betrayed their visual infirmity. The imper- 
fection of their sight has thus been rendered so manifest, that the hypothetically 
perfect vision of others of our race has been assumed to be necessarily the result 
of an exactly opposite condition of the eye. On the other hand, in an albino 
rabbit of the present day, which has probably had some thousand pink-eyed an- 
cestors, the sensibility of the eye has, generations before its time, been adjusted 
to the conditions of its existence; for it is certain that the permanence of any 
variety among animal species is possible, only provided the variation does not 
oustep the limits within which the conservation of life and health is possible. 
Hereditary albinism had in prospect the alternative of total blindness, such as 
characterises the eyeless fishes, and crustacea of the Mammoth Caves of Kentucky ; 
or modified perfect vision, such as it has actually attained to. The modification 
which it has suffered is in reality very small, for what has been lost in one direc- 
tion by the hereditary Albino eye, has been gained in another; if it sees worse 
than a dark eye by meridian light, it sees better by twilight. 
The Edinburgh Zoological Gardens afford at present an excellent opportunity 
of testing the truth of the opinions I have brought forward. They contain an 
albino monkey, an albino rabbit, and several litters of albino rats and mice. 
The genealogy of the monkey is not known, but permanent albinism is believed 
to be as rare among monkeys as among ourselves, and the individual in the 
Gardens exhibits all the peculiarities which characterize human albinoes. I paid 
a visit recently to the Gardens, and found my preconceptions more than confirmed. 
The monkey, a young adult female, is covered with white hair, which gives her 
an aspect of great age; and the overhanging eyebrows, knitted to exclude the 
light, add an air of gravity to her venerable look. But she is a gentle creature, 
and the offer of a nut or a piece of biscuit, brings her at once from a favourite 
shady corner of the cage to the front, where her vision can be readily tested. I 
saw her in the afternoon of a bright sunny day, but not in direct sunlight. Dif- 
fuse light evidently distressed her; the eyebrows were pulled down to the utmost, 
the pupils strongly contracted, the eyeballs in constant oscillation, and the hands 
raised in a most human-like way to shade the sight. Frequently one eye was 
entirely covered, and the other alone employed in vision; and when anything 
