44 Hallier, 
yor to the consumers of beef to have that article cheapened in 
the market by the introduction of animals of such very doubtful, 
not to say injurious, character.“ In plain words, cattle while suf- 
fering either from the chronic or the acute type of this disease 
ought to be withheld from the meat markets. 
5) The period or term of incubation. The term of incubation 
or latent development of the fever poison in the second or nor- 
thern groups of cattle that receive the infection, is clearly proved 
to be a period of variable duration, and that it varies from four- 
teen to thirty or forty days; but that, in the majority of instan- 
ces, the full incubation and development of the disease is accom- 
plished in about twenty days. High temperature manifestly ha- 
stens the development of the disease, and the hunger, thirst and 
excitement of railway transportation aggravates it. But that. even 
where the cattle become infected in good pasture. and under cir- 
cumstances that are favorable to the best health, the incubation 
is certain and destructive: and that with such conditions it re- 
quires four wecks. less or more, to bring the malady forward to 
its stage of obvious symptoms and death. 
6) The susceptibility of different kinds of cattle. The fact 
seems well established that well bred and full fleshed cattle are 
extremely susceptible to the operation of tle contagium, and that 
in them its highest rate of mortality is produced. The fact is 
also indisputable that in the herds that have the misfortune to 
bring the disease or contagium from Texas, only a small percen- 
tage become tatally sick; but in such herds many that do not 
die of the disease linger many weeks in an emaciated and dis- 
eased condition. 
7) Acclimatization and insusceptibility to the cause of the 
disease. This kind of security seems to be enjoyed only by cattle 
that have been bred or pastured south of the Osage and Arkan- 
sas rivers; but whether this partial security against the malady 
is due to the peculiarities of wild cattle, or to a gradually ac- 
quired physiological power to resist the fatal operation of the 
primary cause of the disease while grazing at its very sources, 
does not appear to be proved. 
8) Is the disease due to crowding and abuse of cattle? 
Plainly, it does not originate from such causes; but there is evi- 
dence that the Texas cattle that are crowded upon the „boiler 
deck“ of the Mississippi steamboats, and subjected to thirst and 
