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EXPERIMENTAL ‘‘TICK PARALYSIS” IN THE DUG. 
By SEYMOUR HAD WEN, D.V.Sci., 
AND G. H. F. NUTT ALL, F.R.S. 
(From the Quick Laboratory, University of Cambridge.) 
The following note is published by way of supplement to the 
foregoing paper on “Tick Paralysis” by Hadwen, as it records a positive 
experiment carried out in Cambridge upon a dog experimentally infested 
with Dermacentor venustus obtained from Canada. 
The ticks (4$s and If) were collected about 5. vi. 1913 by 
Mr Stanford from his own person whilst prospecting in the mountains 
near Nelson, British Columbia. 
“ Tick Paralysis ” in the Dog. 
The dog upon which the following experiment was carried out had 
been under observation for close on 14 months at the Field Laboratories, 
Cambridge, having previously been used for experimental observations 
on piroplasmosis. On 17. v. 1912 it was inoculated subcutaneously with 
blood containing Piroplasma canis ; on 2.5. v. a few parasites were 
present in the ilog’s blood and on the following day it was treated in the 
usual way by the subcutaneous injection of lOc.c. of 27 o aqueous 
solution of Trypanblue. The animal promptly recovered from pii’o- 
plasmosis and remained perfectly healthy up to 8. vil. 1913, the date 
upon which our experiment was started, as recorded in the protocol 
which follows : 
