THE RELATION OF DIET TO DISEASE 435 
of their food more nearly to the requirements of these 
mammals. These monkeys also have mouth sacs, which 
enable them to acquire more food per kilo of body weight 
than the smaller Cebidag which are not so advantageously 
equipped. The food even in the amounts consumed by 
the macaques is low in calcium, phosphorus and iron. It 
is very possible that there are enough of these ingredients 
present as a rule, to maintain the animal in organic 
equilibrium, during normal life, and possibly even enough 
to supply the needs of the embryo but not sufficient to 
maintain the young during the period of lactation. A 
few macaques dying during the delivery of young showed 
slight osteomalacic changes in the pelvis. This was 
notably present in one described in detail by 
E. A. Schumann. 
The calcium requirements of the female are always 
much increased during pregnancy and lactation due to 
the withdrawal from the mother to meet the needs of the 
embryo and nursling. Forbes and Beegle(12) found 
that lactating animals made heavy drains on their stor- 
age calcium even when the diet was liberal and the animal 
was storing nitrogen. 
Iron is the essential element of hemoglobin and 
chromatin — the body constituent most directly concerned 
Avith the process of oxidation, secretion, reproduction 
and development. The iron of the food is absorbed from 
the small intestines, enters the circulation through the 
lymphatics, is deposited in the liver, spleen, and bone 
marrow and eliminated through the intestinal walls. 
There is very little iron reserve in the adult body ; and as 
a result any failure of the intake to equal the output 
causes an immediate reduction of the hemoglobin. Voit 
found that the iron eliminated in the feces of starving 
dogs, or dogs on a diet low in iron comes from the body 
through the intestinal walls. Medicinal iron stimulates 
the production of hemoglobin and red blood cells but 
(12) Ohio Agricultural Experiment Station Bull., 295. 
