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felt at first, but the movements made by the tick in detaching itself 
drew my attention to it; bleeding was profuse, and did not stop for 
some minutes. 
In sheep, after a few days, a bruised appearance develops about the 
seat of the bite and persists for some time. 
Position of ticks on the host. 
Out of 108 ticks collected on about 25 sheep on the range, all but 
four of those which had attached themselves were situated along the 
back-bone (one on the brisket, three round the base of the ears). The 
sheep were not all examined very carefully, but a number were turned 
over and the belly and legs searched. Many of the ticks were not 
attached ; they were found loose on the fleece and had evidently been 
picked up recently. 
In my experiments the ticks became attached as follows : 
On lamb I, ten ticks attached themselves within half-an-inch of the 
back-bone on either side, and one at the base of the right ear (PI. XXI, 
fig. 2). 
On lamb III, three females attached themselves along the back¬ 
bone, one male at the base of the right ear, and one female on the 
brisket. 
On lamb IV, two females and one male attached themselves along 
the back-bone (PI. XXI, figs. 3 and 4). 
When first applied the ticks were scattered along the back and 
their movements were not interfered with. Only in one case, that of 
lamb III, were ticks (one male and one female) placed in position and 
watched until they attached themselves. This was done three days 
after the first were put on, as only two liad become attached in the 
lumbar region. It is possible that the second lot of ticks had nothing 
to do with producing paralysis, for the female was barely gorged when 
the symptoms first appeared. 
The reasons for D. venustus choosing the back and neck as its seat 
of attachment are probably as follows: (a) there is frequently a 
parting in the wool along the back, especially in Merinos; {b) the ticks 
are likely to be brushed off on to the backs of sheep when the animals 
pass under bushes ; (c) all the denuded portions of a sheep’s body are 
greasy ; {d) the wool is very thick and close on all other parts of the 
body, except on the brisket, where ticks are occasionally found 
attached. 
