DISEASES OF BLOOD AND BONE MARROW 93 
Among the Rodentia we have had anemias in a 
Beechy's Gopher (Citellus grammurus beecheyi) and a 
Southern {Sciurus niger niger) and Western Fox Squir- 
rel {Sciurus rufiventer). The first had a myeloma also, 
and will be discussed later. One of the squirrels had 
osteomalacia, while the other suffered with diarrhoea and 
showed hydropic degeneration of the kidneys, conditions 
probably due to acute intoxication. 
In Aves. 
The class Aves is represented by the orders Passeres, 
Psittaci, Columbae, Herodiones, Gavige, Picariae, Striges, 
Galli and Accipitres ; the first four are well represented, 
but in the other orders only one or two cases have occur- 
red. The causes of anemia in birds are essentially those 
discussed for mammals with the provision that greater 
attention must be paid to parasites, particularly those of 
the blood. Several slightly varying protozoa inhabit the 
blood corpuscles of birds, and numerous embryos may 
circulate after they escape from a parent lying in some 
organ or tissue. The role of blood parasites, intra- or 
extracorpuscular, in the cause of death or of anemia is, 
however, somewhat paradoxical. Plimmer seems to 
credit a heavy infestation with great value in the cause 
of death. In the human being an infestation of one cell 
in a hundred is a fair grade of malaria ; such a relation is 
apparently common in birds, and we have repeatedly 
seen a much heavier seeding while Plimmer reports as 
many as 70 per cent, of the erythrocytes to be carriers of 
hemogregarines (he has seen 92 per cent, in reptiles). 
Can then the effect upon hemic function and vital resist- 
ance be great? It has been our practice to interpret the 
finding of circulating protozoa or of larval metazoa as 
merely reducing the resistance of the birds so that they 
succumb more readily to incorrect food, strange environ- 
ment or infection. 
