CENTRAL VETERINARY MEDICA1 SOCIETY. 295 
factory to know that we are able to place so important a matter 
beyond tbe pale of doubt. 
It may not be pathologically precise to say that like always 
begets like either in an anatomical or chemical sense where 
disease is transmitted from the lower animals to man, or from 
man to the lower animals, and this for reasons that will be found 
in the diversity of structure and function, food and habits, and 
mode of life. But there is belonging to all these interchangeable 
disorders as they exist in man and beasts, common characters and 
features which bespeak their relationship. Mr. Power points 
out that already we know of several diseases in the cow capable 
of infecting the human subject, and he cites the relations of 
vaccinia to human smallpox, of bestial to human tuberculosis 
and anthrax fever in animals to that of man, &c., all of which 
carry with them from one creature to the other the typical 
features of the group to which they beloug. If this be so, then 
is it not to bovine diphtheria that we should look for any etiolo¬ 
gical relations that may exist between the cow and human 
diphtheria ? 
Considering, however, the utter disregard with wdiich compa¬ 
rative pathology has been viewed in this kingdom, it is not too 
much to assume that bovine diphtheria, like many other animal 
diseases, is not yet known to human pathologists. That the 
milk of cows affected with this disease is not capable of originat¬ 
ing diphtheria in man is shown by the facts I am about to relate. 
In January last an entire herd of forty milch cows became more 
or less affected with this malady. Ten of them suffered very 
severely, one died, and one was destroyed when in a state of 
collapse. The symptoms exhibited by them varied somewhat 
according to the intensity of the attack. The more severe cases 
were ushered in with rigors and diarrhoea ; food was refused, the 
animals became dull and dejected, and the internal temperature 
w r as increased, in some instances 3, 4, or 5 degrees; the pulse 
was quick, and the respiration somewhat hurried. This was 
followed by great prostration, cold extremities, and a harsh, 
croupy cough. As the disease progressed the cough became 
more and more painful, and the breathing embarrassed. Poamy 
saliva fell from the mouth, the throat became enlarged, the 
movements unsteady, and the hoof tympanitic. Dulness in¬ 
creased as the disease went on and culminated in coma. In the 
worst cases death was brought about by asphyxia. Some of the 
animals exhibited a slight cough, with bronchial catarrh and 
some small degree of fever. Such cases which were in the 
majority recovered in from three to five days. I regret to say 
that I had not an opportunity of making a post-mortem examina¬ 
tion, but the gentleman in attendance kindly forwarded to me 
the larynx of the cow that was destroyed, which I have much 
pleasure in laying before you. 
When first removed the false membrane which is now seen to 
cover its mucous surface was much thicker than it now appears, 
LII. 21 
