38 B. C. ENTOMOLOGICAL PROCEEDINGS, 1911. 



found together with the females on the squirrels, nearly 200 females and 

 nymphs were captured before a single male was encountered. This 

 means that copulation between the sexes occurs almost wholly in the 

 squirrels' nests or on the ground. 



The same general life history should apph' also to the ticks found 

 on other nesting animals, such as coons, and perhaps skunks, but to those 

 which move about a great deal, like the mink and martens, I do not 

 think it would apply, nor for bears, which den up after the cold weather 

 has started and would no doubt go into their dens free from ticks. 



Ixodes texanus (Banks) was found twice on coons (Procyon lotor) 

 captured in hollow trees, both times in the dead of winter ; one of them 

 up North when the thermometer was much below zero. The exact 

 temperature was not ascertained, but the trees round about were crack- 

 ing with the frost. 



These observations are further confirmed by the fact that no ticks 

 have been found on the hares (generally known as rabbits) of the 

 lower mainland in the winter, whereas in the summer ticks are almost 

 invariably found on these animals. 



Though ticks are able to withstand low temperatures without being 

 killed, they become torpid when cold, and in my experiments, would 

 not attach themselves to animals unless they had been previously warmed. 

 Once they are firmly attached they are protected by the hair, and are, 

 of course, kept warm by the animal's heat. 



In conclusion I desire to express my gratitude to Professor Nuttall, 

 F.R.S., of Cambridge, for his help and encouragement in the study of 

 these and other blood-sucking parasites, and to Mr. F. Kermode, 

 Curator Provincial Museum, for giving me the scientific names of the 

 various animals I have been working with. 



Ixodes angustus (Banks). 



Gorged, female — Average of 



Oviposition began at 16 days 



Larvae hatched at 73 days 



Larvae fed on rabbit — 



Average time of feeding 2.3 days 



Ecdysis, larvae issue as nymphs 61 days 



Nymphs fed on rabbit — 



Average time of feeding 2.5 days 



Ecdysis, nymphs issue as adults 29 days 



Adults attach and remain for 7 days 



Allowance for hardening of skin after ecdysis and time 



in waiting for host, ten days at each stage 30 days 



221 d 



avs 



Thus it is possible for Ixodes aityiistus to go through its various 

 stages in seven months. 



