204 



the transmission of tlie disease. The author attempted to confirm 

 these observations in 1911, but failed to do so. In 1912 he 

 repeated his observations in the leper asylum at Palo-seco in 

 Panama with ample material. He fed 84 bed-bugs on various 

 cases and in none of these, nor in IT bugs caught on the patients' 

 beds, was he able to detect acid-fast bacilli ; nor was he more 

 successful with 18 others caught on the beds of lepers in the 

 asylum at Trinidad; 86 bugs caught in the Spanish wards m 

 Ancon Hospital in Panama, and 21 others caught in dwellings in 

 Liverpool and used as controls gave negative results. The Ziehl- 

 Neelsen stain was used throughout. 



Hadwen (S.). On "Sick paralysis" in Sheep and Man following 

 Bites of Dermacentor renustns. — Parasitology, Cambridge, 

 vi, no. 3, Oct. 1913, pp. 283-297, 2 pis. 



" Sick paralysis '" occurs in British Columbia and affects man, 

 sheep and probably other animals. The disease is caused by the 

 bites of Dermacentor venustus. It is usually of short duration, 

 is benign in character, but occasionally it persists for long periods, 

 and may terminate fatally. From an economic point of view, 

 the disease is of some importance to the sheep industry. The 

 causative agent has not been discovered, and the disease has not 

 been reproduced by inoculation. The most likely hypothesis is 

 that the tick injects a toxin which gives rise to symptoms ap- 

 pearing coincidently with the complete engorgement of the tick. 

 In three consecutive cases, induced by the experimenter in lambs, 

 paralysis occurred six to seven days after the ticks were put on. 

 In no case did the author fail to produce paralysis through the 

 agency of the tick-bites. It has been proved that D. venusti/s 

 usually bites sheep along the back-bone. No larvae or nymphs 

 were encountered on sheep, and there is no record of their 

 attacking man in British Columbia. 



Hadwen (S.) & NuTTALL (G. H. F.). Experimental "Sick para- 

 lysis" in the Dog". — Parasitology, Cambridge, vi, no. 3, Oct. 

 1913, pp. 298-301. 



The condition of " Sick paralj^sis "' experimentally produced in 

 a dog through the application of a single Dermacentor vemtstns^ 

 female, was the same as that observed in sheep, as described in 

 the preceding paper. The examination of the dog's blood proved 

 negative. The negative results of inoculations and the absence of 

 fever indicate that the disease is not infective, although the in- 

 cubation period suggests the contrary. It is only when the tick 

 begins to engorge or feed rapidly, some days after it has become 

 attached, that its saliva produces pathogenic effects. Where the 

 ticks are picked off or rubbed off early, no pathogenic effects 

 follow. So far as records go, it is only the adult ticks which 

 attack man, or larger animals in Canada. 



