:!!'<; 



Appendix II 



[48] 



their host's retreat and naturally the offspring have a good chance of 

 finding the host when their turn for feeding arrives. 



With the Ixodidae the case is different : the fertilized and replete 

 females must frequently drop from the host when it is on its wanderings, 

 and the offspring may be left stranded in places where they may never 

 find a host. The loss of life in nature must be enormous in the majority 

 of species, for in most species the larva, nymph and adult must each seek 

 a host. The loss of life should be less in those requiring but one host, 

 as in Boophilus, where the tick attacks the host in the larval stage and 

 undergoes its metamorphosis up to the adult stage upon a single animal. 

 The greatest loss of life must of necessity occur in such species as are 

 parasitic upon hosts having no fixed habitat. In other cases, owing to 

 the fact that the host returns to a burrow, nest, or the like, it is pro- 

 bable that there may be less loss of life than in the case where an animal 

 with wandering habits is chosen as a host. It would be interesting to 

 make some numerical determinations of the progeny, especially of various 

 species of Ixodidae, with this point of view in mind. 



The large progeny of the Ixodidae secures their survival in nature 

 in the face of the many difficulties the ticks must encounter in finding 

 their hosts. In the Argasidae these difficulties are much smaller and 

 the progeny is proportionately less numerous. 



Argasidae. 



In the following table I have included all the Argasidae: Argas(A.) 

 and Ornithodorus (0.) of which we know the host relationships. The 

 list includes 12 species and 1 variety: 



Argasidae 

 A. persicus 



A. reflexut 



A. vapertilion.it 



Hosts and habitat etc. of Tick 



Birds : fowls, clucks, geese, turkeys, ostriches, 



quail, wild doves, canaries. Infests chicken 



coops, etc. 

 Man : prevalent in Persia where it infests 



native dwellings. It also occurs in houses 



in Egypt. 



Birds : pigeons, fowls. 



Man : occasionally entering dwellings from 



pigeon coops, or attacking persons having 



to do with pigeons. 



Bats : several species ' ; adults found in the 

 abodes of bats. 



Geographical 



distribution 



(as far as known) 



Africa, Asia, Aus- 

 tralia, N. & S. 

 America. 



Europe, N.Africa. 



Europe, N. Africa. 



1 See Tickt, Part I, p. 39, where the bats are listed. A variety infests penguins at 

 Queenstown, Cape Colony. 





