318 
F. S. E. 
1. The long period of incubation, extending from three 
weeks to as many months or longer, the same being afebril and 
enabling the disease to be present among cattle for a long time 
without exciting any suspicion of the same, and much less its 
recognition. This secret invasion of the disease is all the more 
possible, as by a mild course and insignificant local affection, the 
recovery of the complicated organism is by no means seldom, 
without the disease having at all assumed the feverish or appar¬ 
ent stadium by which it would be recognized. 
2. The chronic course of the disease being the rule which, in 
some cases with inclusion of the reconvalesence, may extend over 
six months, a year, and in extreme cases longer. Further, the 
circumstance that such an animal is, during the entire period, a 
centrum from which contagium is constantly emanating:—these 
are the peculiarities which render the stamping out of this disease 
a task of no inconsiderable difficulty. We find trustworthy com¬ 
munications in veterinary literature, which report the infection of 
healthy animals by such, by which a year or even fifteen months 
-had elapsed since their apparent disease, or even after apparently 
complete recovery. 
3. If we take also the transportability of the elements of 
infection into consideration, which favors the direct conveyance 
of the disease from individual to individual, as also the possibility 
of infection by indirect ways, the question becomes still more 
complicated. 
It is self-evident that the stamping out of a disease having 
these peculiar characteristics is bound with many difficulties. It 
is also as self-evident that we shall be able to attain this much to- 
be-desired end when regulations corresponding to these peculi¬ 
arities come into active and intelligent execution; as we can safely 
assert that the disease at the present day owes its origin entirely 
to the distribution of its infectious elements from an already com¬ 
plicated organism and does not develop abiogenetically. As the 
newly drafted Prussian laws pass silently over the fact that the 
continued introduction of fresh animals into stables infested with 
this disease, thereby continally supplying new food for the same, 
so the disease may continue ad infinitum. If we cannot entirely 
