OAK-LEAF POISONING OF DOMESTIC ANIMALS. 35 
6. The ''summer sickness" of the Utah ranges is identical with 
so-called oak-brush poisoning. 
DISCUSSION OF RESULTS WITH RELATION TO PRECEDING 
INVESTIGATIONS. 
The conclusions stated above are derived entirely from the results 
of range investigations and experimental feeding in the western part 
of the United States. As. has already been stated, very little has 
been published with regard to oak poisoning. The statements of 
Barnes, 1913, and of The Breeder's Gazette, 1909, cover about all 
that has been published concerning oak poisoning in the United 
States, except newspaper notices. The study of oak leaves by Mackie, 
1903, gave results that are in entire harmony with those obtained 
in the feeding experiments at the Salina experiment station, reported 
in this bulletin. 
The extended account by Cornevin is the only detailed statement 
of oak poisoning that has ever been published. A comparison of 
his statements with the results obtained in our experiments shows a 
general agreement, but with certain marked differences. Cornevin 
states that the animals, in addition to the constipation with hard 
feces, which is so marked a symptom in our experimental work, 
exhibit colic, trembling, and bloody urine. These symptoms did 
not appear in the experimental animals in Utah and Texas; the 
microscopic examination, however, showed marked nephritis. Cor- 
nevin states that the pulse is "hard" and that the animals have 
fever. In the Salina cases the pulse was weak rather than hard 
and there was no fever, but, on the contrary, the temperature was 
somewhat lower than normal. It may reasonably be questioned, 
however, whether Cornevin' s statement in regard to fever was based 
on any exact observations, as the use of the clinical thermometer 
was not very common at that time. Apparently the European 
animals were affected in a much more acute and severe manner; 
this is also shown in what Cornevin says of the " lesions," which 
correspond very well to those observed in Utah and Texas, but are 
more marked in the French cases. 
A large part of Cornevin's description is taken up by an account 
of the condition of the urine and a discussion, largely theoretical, of 
the probable relation of the tannic acid in the plants to the hemo- 
globinuria. This phase of the subject is reserved for a later con- 
sideration, after some unfinished experimental work has been com- 
pleted. So far as the work has gone there appears to be no marked 
discrepancy between Cornevin's account and the results obtained. 
PRACTICAL CONSIDERATIONS FOR RANGE GRAZING. 
So far as these investigations have gone the following statements 
appear to be justified: 
1. During the summer and fall the oak-brush ranges of Utah can 
be used for grazing, not only with no harm to cattle, but with posi- 
tive benefit. 
