260 QUEENSLAND AGRICULTURAL youRNAL. [1 Ava., 1901. 
I have consequently sought to exactly define the function of the ‘ticks, 
and to consider if there were not a possibility of malarial infection from other 
causes. 
It will be seen that my researches, although subsequent to those remark- 
able researches of Smith and Kilborne, are not wholly devoid of interest. 
: EVOLUTION OF THE TICK (Boophilus bovis, Curtice). 
I could indulge in a long dissertation on the zoologie study of the tick, 
but 1 believe that it is my duty to reserve this description for a special work. 
In this present work I shall confine myself solely to the points bearing directly 
on the disease which now occupies our attention. Besides, the photographs of 
some of my preparations will furnish complementary explanation. 
When I made my inquiries, I had not seen the translation of Smith and 
Kilborne’s book, in which are quoted the labours of C. V. Riley,* Cooper 
Curtice,t and George Marx,{ so that, not having been able to procure these 
mémoires before this work goes to press, it will not be possible for me to speak 
of them now. However, Smith and Kilborne state that Cooper Curtice had 
observed the skin cast twice at a week’s interval, before the tick was adult; 
they also describe other important facts which have been confirmed by my 
researches. 
The tick is known in the Argentine Republic under the name of 
Garrapata. 
It holds the following place in the animal kingdom :— 
Branch ... 035 ox: ... <Anthropodes. 
Class wm 30 a0 ... <Arachnides. 
Order one om _ ... Acartens. 
Family ... 236 019 ... Laodides. 
Sub-family os — ... Lxodines. 
Genus... x0 xx) . Ixodes or Rhipicephalus. 
There are, in different parts -of the world, many species of ticks, That 
species under notice has received the name of Irodes bovis (Riley) and of 
Boophilis bovis (C. Curtice). Some authors cannot connect this species with 
the Rhipicephalus. 
I here give the résumé of one of my observations, which will give an exact 
idea of the evolution of the tick :— 
On the 8th March, 1899, I placed on a bullock several hundreds of ticks 
hatched out on the previous evening. They were then of a russet-brown tint. 
Including their proboscis, their length was 8°80 m.m.; their breadth, measured 
between the two posterior pairs of legs, was 0°55 mm. (Fig. 1, Plate X.) 
These ticks, placed on the bullock in little heaps, disappeared as if by enchant- 
ment ; they melted away, so to speak. Soon they were all hidden under the 
hair, and started on a voyage of discovery to find a favourable spot in which to 
insert their rostrum—the inside part of the thighs, the testicles or the udder, the 
perineum, and the inside surface of the fore-arm are the spots for which they 
have the greatest predilection. 
The hexapodian young larve, whose agility, especially in very hot weather, 
is surprising, are at this stage well adapted to cling to, and to spread over, their 
host. At the extremity of each foot are two large hooks and a small sucker 
(air-hole). (Plate X., Fig. 4.) 
The rostrum (Plate X., Fig. 2) is formed, taking it from below to above, of 
the maxillo-labial dart, constructed of two similar limbs set against the median 
line, and furnished with several rows of teeth of almost equal size, set 
backwards. 
*C. V. Riley, Ixodes bovis: Bureau of Animal Industry, 1868. 
+ Cooper Curtice, Boophilus bovis: Journal of Comp. Medicine and Veterinary Archives, 
July, 1891, and January, 1892. : 
. George Marx, Proc. Entomological Society of Washington, II., p. 232. 
