Biology of I. angustus 315 



H. Beauregard is quoted as having once observed a similar tumour 

 beneath a man's clavicle, and Dr Choupe has seen several such cases in 

 his practice. According to Blanchard nymphs occasionally penetrate 

 beneath the skin of horses, producing furunculosis. He is doubtless 

 referring to the case reported by M£gnin (1867, R4c. veterin., redescribed 

 1892, p. 56 ; in the earlier paper he referred the ticks to a uew species : 

 " Ixode penetrant "). In this case a horse at Versailles was suffering 

 from numerous pustules on the legs. These pustules are stated to have 

 been due to ricinus nymphs ; a nymph was extracted from beneath the 

 scab on each pustule after which the horse recovered. Megnin (1892, 

 p. 62) attributes the penetration of this tick beneath the skin to the 

 structure of its mouthparts. Kossel, Schiitz, Weber and Miessner 

 (1903, p. 40) state that the nymphs and larvae occasionally bore them- 

 selves beneath the skin of cattle. 



The penetration of ticks beneath the skin is certainly an unusual 

 proceeding. It is interesting to note, especially in the case reported by 

 Blanchard, that a tick may survive being embedded beneath the skin 

 for a considerable period of time. 



Ixodes ricinus var. scapularis. 



Hooker (1908 a, p. 43), in the United States, records that he has 

 observed the sexes of this species coupling both on and off the host. 

 He writes : " An unengorged, unattached % , taken in the field from a 

 hunting dog and placed in a pill-box with unattached Js taken from 

 the same dog, was shortly after found coupling with one of the latter. 

 From this it would appear that it is unnecessary, for the ? of this 

 species at least, to take food prior to fertilization." 



Ixodes angustus. 



According to personal communications received from Dr S. Hadwen, 

 this species occurs in all stages upon squirrels at Duncan's, in British 

 Columbia. The ^s are scarce. He succeeded in raising adults from 

 nymphs captured on squirrels by transferring them to rabbits in 

 captivity and allowing them to feed upon the rabbits. 



Coupling has been repeatedly observed by Dr Hadwen. In one case 

 it lasted 15 minutes after the ticks were placed together in a tube. 

 When the £ withdrew his mouthparts from the vulva the vagina was 

 seen to be slightly everted. Slight pressure applied subsequently to the 



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