640 MEDICAL ENTOMOLOGY 



with great ease by adopting the methods recommended in the case of 

 savignyi. 



All the other species of Ornithodorus except O. megnini the habits 

 of which have been observed appear to have the same life history as 

 savignyi and moubata, each passing through four nymphal stages before 

 becoming adults. O. megnini is very peculiar in its feeding habits. 



The ' Spinose ear tick ' the popular name of megnini in the United 

 States is chiefly found on the horse, occasionally on cattle ; sometimes 



. it attacks man. As its name implies, it attaches itself 

 Ornithodorus megnini . . . , 



to the ear, often passing inside and burying itself 



deeply in the skin. Hooker has studied its habits. He placed the 

 larvae in cloth bags (see page 644) which were fixed over the ears 

 of cattle. The larvae soon buried themselves deep down in the folds 

 of skin. About five days later, and while still attached, they shed their 

 skins and became nymphs ; these remained on the cattle for several 

 months, during which time they slowly became replete. They then 

 detached themselves, and on dropping to the ground (the bags being 

 removed) crawled up the wall or wooden posts in the pen and hid in 

 cracks and crevices several feet above the ground ; after about a week the 

 final metamorphosis took place. This stage, according to Hooker, does 

 not feed ; unlike all the other species of Ornithodorus the habits of 

 which are known, the female megnini lays all her eggs in one batch and 

 dies. It should be noted that megnini has only one nymphal stage. 



The life histories and habits of ticks of the genus Ixodes (including 

 the subgenera Eschatocephalus and Ceratixodes) are typical of the 



family Ixodidae. As far as is known all the species 

 Genus Ixodes ... 



require three hosts, which may belong to the same or 



to different species. As regards their habits these ticks come nearest to 

 the Argatini. Nuttall, in his valuable papers on the subject, points out 

 that a large number of the males of Ixodes are unknown, and that this is 

 mainly due to the fact that they are never found attached to the 

 vertebrate host, but remain in their burrows or nests, where they seek 

 the females for copulation. In this habit these ticks recall some of the 

 species of the genus Argas, for instance, as Argas vespertilionis and 

 Argas bnimpti. On the other hand the males of many Ixodes, like most 

 Ixodinae, are to be found with the females on the host. 



Nuttall has recently recorded some valuable observations on the life 

 processes of several species of Ixodes ; as these observations have a direct 

 bearing on the carrying out of laboratory experiments necessitating the 

 manipulation of the ticks they are here summarized. It should, however, 



