DISEASES OF BLOOD AND BONE MARROW 89 
is an irregular hyperplasia of the marrow, which is 
usually more marked in the latter. In osteomalacia one 
finds irregular areas of congestion or even hemorrhage 
besides masses of a gelatinous fatty tissue while scattered 
about are pink spots where the marrow is better pre- 
served. In rickets, on the other hand, the tissue is more 
uniformly congested and less sharply separated from the 
endosteal osseoid material or the irregular epiphyseal 
spongiosa. The fibroid or osteoid growth of osteomalacia 
seems to be fairly well differentiated from the marrow 
tissue although it may send strands into the canal and 
across the spongy area. Histologically there is not a dis- 
tinct difference in the appearances nor do they differ 
from the human analogue. In those cases which develop 
late in life the red cell centres are very few in number but 
usually active. In the blood, one finds a few nucleated 
and stippled cells, but not much change in size and shape 
of the erythrocytes. 
It does not seem that the anemia can be the cause of 
death, for among our thirty-nine cases of osteomalacia 
and rickets, the prosectors have thought it of sufficient 
importance to record in the diagnoses but eleven times. 
There are usually complications of pneumonitis or enter- 
itis to finish the animal before the poverty of the blood 
will do so, and our records show only a Black Spider 
Monkey (Ateles ater), a Silky Marmoset {Leontocehus 
rosalia) and a macaque (sp.?) with osteomalacia and 
grave secondary anemia. It would seem, however, that 
hemoglobin anemia must exist, for, despite one record of 
40 per cent., Fleischl, no excess of pigment deposit is 
noted in the spleen, liver or marrow. 
Carnivora have shown a moderate number of diseases 
of the skeleton but the occurrence of a marrow involve- 
ment seems less frank, although the anatomical changes 
are similar. However, there are three grave secondary 
anemias recorded in eleven carnivores suffering from 
osteomalacia and rickets. Another prime cause of low 
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