ON INFLAMMATORY FEVER IN CATTLE. 567 
own immediate structure, along with the extravascular blood they 
contain, becomes placed in large quantities beyond the natural 
organic functions, and contributes, by the decomposition necessarily 
involved on such cessation of vital action, to the formation of gas, 
which forms a characteristic feature of swellings situated where 
much cellular tissue exists. 
Causes . — The predisposing causes of this disease are connected 
with the age, food, sex of the animal, season of the year, and 
plethora. The proximate cause I consider exists in the blood itself. 
Age . — It is consonant with the observation of all, that inflam- 
matory fever occurs to a far greater extent among animals under 
two years of age than in others. Cases of this disease do occur 
sometimes in adult animals ; but from their rarity they may be 
considered as exceptions to the general rule rather than otherwise. 
Food . — We find again that the disease seldom appears in house- 
fed stock, but it is prevalent among young animals, living in 
luxuriant pastures and thriving rapidly, and is always to be 
dreaded as a consequence of such condition. It is very seldom 
observed among those that are ill fed and in lean condition, and 
on making its appearance in a stock of young cattle those first 
fall victims that have been feeding or growing with the greatest 
rapidity, and are in a plethoric state of body — those in leaner and 
less thriving condition being attacked latest, and frequently escaping 
altogether. 
Sex. — Altogether, neither breed nor sex are exempt from its 
attack. Short-horned heifer calves appear affected in greater pro- 
portion than males and coarser bred animals. 
Season . — Provided the season during May and June is warm 
and otherwise favourable for the rapid advance of vegetation, in- 
flammatory fever is often of such frequent occurrence in districts 
where much young stock is kept as to assume an enzootic or even 
epizootic character. During the summer months cases will some- 
times occur, yet not in the same proportion as earlier in the season; 
but when in a genial autumn the young animals are turned into 
rich after-grass, we have again a marked recurrence of the disease, 
almost as frequently as in the spring. 
Seeing, then, that the conditions just stated are those under which 
inflammatory fever most commonly makes its appearance, and are 
popularly accounted its causes, we are led in the next place to 
consider how they actually operate on the system, so as to induce 
the proximate cause or development of the disease. So accustomed 
are we to associate certain states of the body with certain diseases, 
that too frequently we rest satisfied with the apparent cause and 
effect as naturally allied, without reflecting upon or endeavouring 
to account for their true relation to each other. 
In the present day, attempts to explain the causes or nature of 
