380 
AGRICULTURE: HART, AND OTHERS 
is probable that the motor disturbances observed in the animals can be 
referred to the oedematous condition of the nervous tissues. The cause 
of beri beri is ascribed to the absence or deficiency of certain essential 
factors in the diet, particularly to water soluble B. In the case of ex- 
cessive wheat feeding it would appear that the essential causal factor 
for disaster to growth and reproduction is a toxic substance which either 
interferes with the utilization of materials necessary for the full develop- 
ment of the nervous system of the animal or directly with the normal 
functioning of this tissue. This would account for the blindness ob- 
served in some of the heifers and also for the failure of muscular co- 
ordination apparent in the new born calves produced on rations of large 
whole wheat content. 
It was also apparent that rations producing an early delivery of off- 
spring would usually lead to a failure of the animal to remove properly 
the afterbirth, with its attending dangers of infection; and an over- 
abundance of a material like wheat straw in a ration, owing to its low 
salt content, becomes an important factor in premature birth. 
An observation in our experimental work of interest to veterinarians 
was the low resistance to other diseases of the mothers fed the wheat 
ration. In an outbreak of anthrax in the university herd the only losses 
to occur from this disease in our experimental herd were among the 
wheat grain fed animals. 
The principle^ laid down as to what factors must be present in a ra- 
tion of natural origin in order that it becomes efficient for both growth 
and reproduction is well supported by these data. This principle pos- 
tulates that there must be present efhcient proteins, adequate energy, 
proper salt mixture, fat soluble A and water soluble B (vitamines) and 
an absence of toxicity or a toxicity of such mildness as to become inoc- 
uous in the presence of the other normal factors of nutrition. The 
presence of toxicity in the wheat kernel as the explanatory factor for 
these records rests not only upon the evidence secured with swine and 
rats but also on that presented here. // is not a deficiency phenomenon. 
A wheat grain, corn stover ration often failed, not only when used alone 
but when there was added to it the most likely limiting factor, fat soluble 
A, as butter fat. 
The recognition of these normal factors of nutrition and the further 
recognition of the occurrence in apparently normal food-stuffs of sub- 
stances of mild toxicity will be of immense advantage in arriving at an 
understanding of the oft reported troubles with farm animals which 
today are either not understood or their etiology wrongly assigned; and 
in the field of human nutrition the same principles will apply. 
