448 QUEENSLAND AGRICULTURAL JOURNAL. [1 Dec., 1898. 
“Texas fever” is open to no such objections. It involves or implies no 
such errors. It is simply a name of local origin to express the disease we have 
to consider, whose essence is known to bea certain peculiar blood infection. 
ANALYSIS OF THE TICK PLAGUE. 
lf we, as it were, resolve the tick plague into its constituent parts, we find 
that there are several distinct factors at work, with each of which we are all 
pretty familiar. My object is not so much to discuss these factors individually, 
but to endeavour to trave out the relations which they bear to each other, and 
the relative parts they play in the production of the tick-plague drama. The 
actors are the tick, the microparasite, the bullock, and the fever—which may 
perhaps be held to represent the music; with—if you will’ allow me to 
complete the picture—the discomforted owner as audience. 
In this cast, the chief characters which we shall have to consider are the 
microparasite and the tick. The interest of the piece indeed lies largely in the 
combined machinations of these two for the accomplishment of their wicked 
purposes. ‘The microparasite, it must be clearly understood, plays throughout 
the part of first villain. 
THE PART PLAYED BY THE TICK. 
The cattle tick—and ‘in speaking of the cattle tick I do so without prejudice 
to the possible claims of any closely-related variety, or even distant cousin, 
to beincluded in my remarks—is, I am. inclined to think, a, rather maligned 
and inisunderstood character, or is at anyrate not quite so black as he is some- 
times represented. His sinister repute is due chiefly to that unreservedly bad 
character the microparasite, with whom he is, unfortunately, so often associated. 
The microparasite merely uses the tick to effect its ovn—and from our point 
of view, highly objectionable—purposes ; and, as not infrequently happens in 
such cases, the tick gets all the blame. Anyway we know that the tick him- 
self, when free from his microscopic .and mephistophilean associate, is a 
comparatively harmless fellow, in that he does not at anyrate produce Texas 
fever. or it is a matter of common experience that the tick may be, and very 
frequently is, present upon susceptible cattle for a considerable time—for many 
months, or it may be for years—before any Texas fever breaks out amongst 
them. It has also been shown by experiment that such infested cattle contract 
the fever at once if removed to a place where the ticks are known to be charged 
with the germs of the disease. So that the mere preseuce of ticks, even when 
they have been present in large numb. rs for a long time, in itself affords no 
immunity against Texas fever. It has also been shown that the blood of such 
infested but still susceptible cattle causes no reaction when injected into clean 
animals, and confers no immunity. ; 
The relation of the tick to Texas fever in cattle appears to be precisely 
parallel to the relation of the mosquito to malarial infection in man. The 
mosquito is now very generally recognised as the agent by which the malarial 
germs are inoculated into our blood, but for all thatit is perfectly certain— 
and very fortunate for us—that all mosquitoes are not charged with these 
germs, and therefore convey no. such disease. And the tick, when free from 
the fever germ, is no more capabie of setting up Texas fever than is the 
mosquito, when similarly free, of causing malarial infection. 
It has to be admitted, however, that ticks which do not cause ‘l'exas fever 
may yet, undoubtedly, cause heavy Josses in other ways. For they tend, when 
in large numbers, to impoverish and wear down the cattle,, particularly cattle 
that have not yet become inured to. their presence, and such as are already 
impoverished in, bad seasons by the want of sufficient good grass. , , 
The precise way in which ticks kill cattle apart from the specific disease— 
Texas fever—is not thoroughly known. It seems possible they exert their 
deleterious influence, in part at. anyrate, in the way generally supposed—viz., 
