GENERAL PATHOLOGY OF u SUPRA ” IN ANIMALS. 585 
our journals are at once instructive and suggestive. Coming 
fi oni the pens of experts, from those who have had much per¬ 
sonal acquaintance with the disease and those who have 
studied its natural history and pathology, they form a valua¬ 
ble collection of opinions which serve to illustrate the difficul¬ 
ties of inquiry and the obscurity that still dominates the sub¬ 
ject. The need for investigation is clearly shown, but the 
complexity ol the questions to be investigated is manifestly 
great. Many of the writers furnish lists of propositions re¬ 
garding the classification of the parasite; some indeed limit¬ 
ing themselves to these, whilst others deal more generally 
with the subject. It could hardly be expected that anything 
like unanimity of view should prevail, and without attempting 
to cover the whole ground, it may be useful if we submit a 
few suggestions upon moot points regarding the disease. In 
the first place, there is considerable divergence upon the es¬ 
sential nature of surra. I. V. S. Evans was the first who 
noted the presence of parasites in this disease, but he did not 
identify the malady. Mr. Steel stands alone in the belief that 
it is “ a form of relapsing fever in the horse/’ Most veterin¬ 
ary practitioners who have studied the disease, as well as 
acknowledged bacteriologists, show that there is nothing in 
common between the two affections. Indeed, Dr. Vandyke 
Carter himself cannot see any identity between the parasite of 
surra and the spirillum common to relapsing fever in man. 
Surgeon-Major Ranking contends that surra is, in fact, ague 
in the horse. Indeed he thinks that at present there is^no 
other deduction from the facts, and thinks he has obtained 
further evidence in support of the opinion he has formed as 
to the identity of the plasmodium malarias and the bacillus 
malarias in man. He advances reasons for his belief that the 
general view of the plasmodium being considered as a proto- 
zoon is also incorrect. And he points out facts in support of 
his arguments that surra and ague are equivalent diseases. It 
is by no means necessary to the truth of his argument that 
such is the case, as he relied upon the diagnosis of veterinary 
surgeons that the disease he investigated was surra, and “the 
diagnosis was borne out by its fatality." Although we can- 
