ZOOLOGICAL 
SOCIETY. 
BULLETIN 
Published by the New York Zoological Society 
VotumME XXIV 
NOVEMBER, 
1921 NuMBER 6 
ALBINOS IN THE ZOOLOGICAL PARK AND ELSEWHERE 
By Raymonp L. Dirmars 
Illustrations from photographs by Elwin R. Sanborn 
N a period of over twenty years in a zoologi- 
cal park, there are many opportunities to ex- 
amine specimens that vary from the typical 
forms they represent. We think that the Park 
offers for such observations a wider field than 
the average natural history museum. All of our 
animals are transient, and must be replaced, and 
the realization of this causes us to be constantly 
in touch with collectors, whose observations and 
eaptured material add largely to our records. 
The purpose of this article is to cite our records 
as to the occurrence of albinism in our collec- 
tions. 
Albinism is due to the lack of color pigment 
in the skin, affecting the external covering of 
hair, feathers or scales, according to the nature 
of the subject. An albino mammal or bird is 
pure white, owing to the lack of coloring matter 
in pelage or plumage. Albinos with a bare in- 
tegument or with scales like the reptiles and 
fishes are usually of pinkish coloration. The 
indicated pinkish hue results from the blood 
and muscular tissue showing through the par- 
tially transluscent skin. The eyes usually ap- 
pear pink, the pupil but faintly indicated, ow- 
ing to the lack of color in the minute muscles 
of the iris. Owing to the lack of this shielding 
color, permitting light to filter throughout the 
area of the iris, and consequently rendering 
ineffective the contraction of the pupil in rays 
of strong radiance, in a strong light the pure 
albino suffers from “halation” of vision. In 
a light so subdued that the pupil would normal- 
ly dilate to cover the greater part of the iris, 
the animal sees perfectly well. The extent 
of albinism may be immediately noted by an 
examination of the eyes, and the gleaming pink 
iris, denoting the reflection of blood within the 
eye-ball, points to a purely albinistic example. 
Studies of albino snakes are particularly in 
teresting, as the more vivid color patterns still 
are indicated to greater or less extent, seldom 
being altogether absent. The writer has noted 
specimens with perfectly pink eyes, that were 
faintly ringed or blotched with yellow or sal 
mon markings, correctly representing the loca- 
tion of pitchy black patterns on normal speci- 
mens. 
Excluding all domestic types, the Zoological 
Park has exhibited albinos of the following 
species: 
Ring-tailed monkey, raccoon, gray squirrel, 
Canadian porcupine, woodchuck, fallow deer, 
common opossum, jackdaw, crow, peacock, 
pheasant, quail, sparrow, rhea, alligator, rattle- 
snake, milk snake, garter snake, palm viper, 
South American tortoise and pond frog. 
The list presents a fair demonstration of 
albinism among the classes and orders of mam- 
mals, birds, reptiles and amphibians. We real- 
ize albinism is due to the caprices of nature, 
and that so far as scientific investigation is 
concerned there are grave barriers to a defi- 
nite solution, but we are, nevertheless, led to 
form several conclusions. 
It is our belief that albinism is 
lent among the rodents than in any of the other 
In reaching this conclu- 
more preva- 
orders of mammals. 
sion, the writer has given full consideration 
to the fact that the rodents form an extremely 
large order, with very abundant representatives 
of many of the genera. Nevertheless, in com- 
paring this order with other orders among the 
mammals, we fail to note, from records gath- 
ered during twenty years, any mention of the 
albinos among the in 
tremely rare instances, and not always from 
carnivores, except ex- 
