Ticks and Disease. 
275 
parasites, which have hitherto been too much neglected. 
The study of the diseases themselves is, of course, a patho- 
logical matter, and a large number of very able pathologists are 
now devoting themselves to their investigation. But they 
naturally look to the zoologist for co-operation. They find 
certain ticks on the diseased animals, and capable of trans- 
mitting the sickness to perfectly sound animals, and they 
require to know what particular species of tick is in question, 
its area of distribution, and the details of its life-history. It 
seems to be the clear duty of all economic zoologists to lend 
what aid they can, and to relieve the purely medical inquirers 
as far as possible from the loss of time involved in the investi- 
gation of a part of the subject for which their previous 
experience has not specially fitted them. 
Fig. 3. — Ticks laying eggs. 1 
Holding this view, I thought it advisable to accede to the 
request of the Government Entomologist of India, that I should 
examine a large number of ticks collected in that country from 
domesticated animals in various localities, with a view to their 
identification. Through the kindness of Dr. Nuttall I have 
also had access to a large collection of ticks from all parts of 
the world, and the study of these animals has occupied most 
of the time not taken up by the routine work of the depart- 
ment during the past summer. 
Ticks are members of the great group of Acari or mites. 
They are, indeed, the most familiar examples of the group, 
1 Figs. 3, 4, 9, and 13 illustrating this paper have been kindly lent by 
Mr. E. G. Wheler. Figs. 5, 6, 7, and 8 also illustrated this author’s article 
on “ Louping 111 and the Grass Tick” in the Journal, Yol. 60, 1899, pp. 
626 - 644. 
T 2 
