Gr. H. F. Ndttall 
103 
The symptoms described iii the human subject agree with those observed 
in experimental cases in the sheep and dog, and the symptoms noted in 
cases occurring in sheep in the field. The 13 cases recorded by 
Temple in Oregon are of great interest, and in their symptomatology 
appear in most of the cases to agree fully with the cases briefly 
reported by Todd from British Columbia. 
It is to be regretted that we have not more precise data as to 
the species of ticks concerned in the causation of the human cases. 
Todd and Temple merely refer to “ ticks.” It is true that Temple 
sent “ three ticks from Eastern Oregon ” to F. C. Bishopp and W. D. 
Hunter for determination, and that they proved to be Dermacentor 
albipictus, D. veniistus and Ornitliodorihs megnini^ respectively. The 
last-mentioned species of tick has probably nothing to do with the 
case, and it is not stated where and how the other two ticks were 
collected. It is suggestive, however, in view of the experimental 
results, previously cited, that D. venustiis is found in Oregon where 
Temple’s cases occurred. 
Having formerly lived for a number of years in the Western United 
States and collected many ticks from my person on expeditions into the 
mountains, I may say that it was my custom to take a fine comb with 
me and to remove the ticks which so frequently attached themselves in 
the hair at the back of the head and neck. I still have some mounted 
specimens of Dermacentor collected in this manner as long ago as 1879 
in California. It was a frequent occurrence after a day’s shooting in the 
brush to remove several ticks with the comb. Too much importance 
might, therefore, be attached to the finding of a tick or two upon the 
head in children suffering from supposed tick paralysis, for it is 
reasonably certain that ticks would be frequently found on normal 
persons if they were looked for with equal diligence. The cases 
reported by Todd and by Temple, in which ticks were found attached 
to the head, might well be explained as due to mere coincidence. 
That we are dealing with a definite affection, however, has been 
rendered certain by the experimental results obtained by Hadwen on 
sheep and by Hadwen and Nuttall on the dog. 
No particular species of tick appears to be concerned in the 
causation of tick paralysis, since Dermacentor venustiis in British 
Columbia (? and Oregon) and Ixodes pilosus in South Africa both 
^ This tick, the well-known “ spinose ear tick ” of American authors, has not been 
found before so far to the north as Oregon ; it was found in a man’s ear, its usual site of 
attachment to a host. 
