1 Ava., 1901.] QUEENSLAND AGRICULTURAL JOURNAL. 269 
Autopsy.—The lesions found at the post-mortem were those of hemorrhagic 
septicemia; the urine was not hemoglobinuric, and did not even contain albumen. In 
the kidneys, which were slightly congested, | found no hematozoa whatever, nor in 
the cardiac muscle, the spleen, or the capillaries of the mesentery. The cultures of 
the blood and the organs showed various microbes, especially a little bacterium not 
taking the stain of Gram. 
All these negative results might depend upon the method of inoculation. 
I also tried punctures and scarifications. 
The punctures were made in considerable number with needles dipped in 
the blood of ticks lately hatched, or in the product which resulted from their 
being crushed in sterilised mortars. I was very careful to disturb only the 
superficial part of the skin, and, after the operation, the part punctured was 
either rubbed or not with the product of inoculation. 
Whatever precautions were taken, whatever the number of punctures, 
whatever the quality of the products injected, never have 1 obtained a positive 
result. This inocuousness of the punctures thus contaminated is probably the 
consequence of the special properties of the-passive spores, since the virulent 
blood containing the active spores, injected under the same conditions, easily 
induces malaria. It is these experiments which have been many times 
repeated, also the positive results always obtained without any modification 
either of the hematozoa or of the disease in forty-two successive passages by 
sub-cutaneous or intra-venous injection, which have led me to reject the 
hypothesis of a new evolution of the spore in the body of the ticks or in the 
contents of the eggs, after which the micro-organisms might develop easily in 
the red corpuscles. 
I am, on the other hand, quite disposed to admit a special action of the 
tick due to the deposit of a saliva or of a certain venom, analogous in its action 
to that of the virus of the bovine plague. (See especially Nicolle and Adil-Bey, 
Annals of the Pasteur Institute, 25th April, 1899.) 
The puncture of the ticks, as I have been able to observe, is followed by 
an inflammation of the tegument which is never produced by artificial 
punctures more or less contaminated. Surrounding the rostrum of the tick 
(I have carefully noted this) may be seen quite at the beginning of the 
puncture, on the parts deprived of pigment, a roseate halo, replaced later on by 
. a true inflammation of the skin with serous infiltration. ‘ 
By means of the poison secreted by the tick, small in quantity, but 
continued to the base of the puncture, the blood becomes less resistant and the 
spores of the Piroplasma bigeminum would then find themselves in conditions 
favourable to their development. 
To sum up my opinion of the particular réle of the tick in the transmission 
of bovine malaria, I will say this— 
The tick, in the larva stage, serves as an intermediary between the Péro- 
plasma bigeminum and the beast. It conveys hematozoa in the form of passive 
spores, which it has received either whilst in the egg or in contaminating 
its rostrum after having hatched out.* 
At the instant when it fixes its rostrum in the skin of an animal, it injects 
the spores, and at the same time its venomous saliva, the action of which 
fayours the development of the latter. 
REFUTATION OF THE OBJECTIONS RAISED AGAINST THE PART 
PLAYED BY. THE TICK IN THE PROPAGATION OF THE 
MALARIA. 
What we now know of the evolution of the Piroplasma bigeminumand of that 
of the tick enables us to reply, better than has been done up to the present, to 
the objections opposed to the part played by these Ixodes in malarial contagion. 
T shall only consider the principal objections. 
* T admit that the two causes may exist simultaneously. 
