306 QUEENSLAND AGRICULTURAL JOURNAL. [1 Apri, 1899. 
within the ticks and in the blood of cattle. Jf these minute organisms are 
absolutely dependent upon the ticks for their existence, we would destroy them 
by eradicating the ticks; but if the protozoa may live an independent life in 
the more or less stagnant waters or marshes of the South Atlantic and Gulf 
‘Coasts it would be hopeless to attempt to annihilate them entirely. 
Without the ticks, however, the protozoa would be of simply local interest. 
Even if the native cattle became infected by drinking contaminated water they 
could not spread the disease, and no cattle would suffer except those raised in 
or taken into the comparatively small area in which these special conditions of 
high temperature and slow-running or stagnant water exist. We may admit, 
therefore, provisionally at least, that the destruction and extirpation of the 
fever tick means the eradication of the Texas fever contagion in the greater 
part, if not all, of the territory of our Southern States. 
In at least half a dozen counties in Virginia where the fence laws prohibit 
the running at large of cattle the ticks have soon disappeared, and these 
counties have been placed above the quarantine line without any loxs having 
since occurred through contagion spread by the cattle from those sections. 
From a number of farms, and particularly the farm of the Georgia Experiment 
Station, the ticks have been eradicated by picking them off the cattle by hand 
and destroying them as fast as they became large enough to see. Two years, 
‘have been sufficient to accomplish this result. Now.the interesting fact has 
been demonstrated that northern cattle taken to such farms no longer contract 
Texas fever. This strengthens our theory that in much of the southern 
territory at least the protozoa are not obtained by the cattle from the soils or 
waters, but that they must be inoculated by the ticks. 
Accepting this theory then as demonstrated for some parts of the infected 
‘district and as probable for the greater part of it, and we are led to ask, What 
is the least expensive and most feasible method of eradicating the ticks? The 
first step is undoubtedly to prevent cattle from running at large and continu- 
ally gathering up and bringing in a fresh supply of these parasites. The home 
cattle must be kept at home, and no other cattle should be allowed to come 
upon the premises. The second step is to prevent any ticks from maturing 
upon the cattle. 
It appears that the ticks must pass a considerable part of their life upon 
cattle in order to perpetuate their species. Young ticks hatched in the spring 
may live upon pastures during the whole summer, but they remain very small, 
are unable to multiply, and die upon the approach of winter. In just what 
form the tick survives through the winter is not definitely known to the writer, 
As these parasites are observed to remain on cattle for a long time in cold 
weather, it is probable that some of them pass the most dangerous period 
yrotected by the hair and supplied with warmth from the animal’s body. 
Hither the live ticks or their eggs, it is uncertain which, may also survive the 
winters as far north as the quarantine line when protected by leaves and brush. 
But if they do not meet with cattle and mature upon them the following 
summer they all perish. ; 
The possibility of these ticks maturing upon other species of animals is a 
‘question of consid: rable importance in this connection, but unfortunately 
cannot be comyletely and satisfactorily answered. The Texas-fever tick is a 
cattle tick, and does not readily grow upon other animals. It is often found 
upon horses and mules, however, but the fact that Texas-fever outbreaks have 
seldom if ever been traced to contagion carried by these animals seems to 
indicate either that the ticks raised upon them are not fertile and fail to repro- 
duce themselves, or that because the equine species does not harbour the 
microscopic protozoa the young ticks from mothers raised upon horses and 
mules do not bear the contagion. These points should receive close investiga- 
tion. In the meantime it may be assumed that the ticks may be eradicated 
from pastures or farms by preventing any of them from maturing for 1 year, 
-or at the most 2 years, upon bovine animals. 
ere 
