62 
Adaptation of Ticks 
Number of Geographical 
Host’s times found distribution 
Species habits Host thereon of tick 
I. vespertilionis. Bats only (g found in caves etc. inhabited by bats). 
0 Plecotus auritus ... ... Europe, Africa, 
0 Ebinolopbus bipposideros Australia. 
0 ,, ferrum equinum 
0 ,, euryale 
0 ,, bippocrepis 
0 ,, blasius. 
0 ,, elivosus 
0 Vesperugo pipistrellus 
0 ,, tricolor. 
Ixodes putiis and vespertilionis are solely parasites of birds and bats, 
although putus may occasionally attack man when he approaches the 
infested birds’ nests. 
With the exception of I. hexagonus'^, including var. cookei, of which 
we have no particulars, the males of these species have never, apparently, 
been captured upon the host. On the other hand, the males of the other 
species have been found in the habitats of their hosts: canisuga in the 
nests of sand-martins (bank-swallows) and in a dog kennel, vespertilionis 
in caves inhabited by hoXs, putus in and about the nests of marine birds. 
In such localities the males would have ample opportunities of feeding 
upon their hosts for brief periods after the manner of male Argasidae, 
assuming that they do feed. It is conceivable, however, that such 
habitat-infesting males may not be blood-suckers at all. We have seen 
that Ornithodorus megnini f does not feed, and that it nevertheless 
fertilizes the female. The same may hold for certain Ixodidae fs. 
The matter requires further investigation. The sexes of canisuga and 
jmtus have often been observed in copula apart from the host, and it 
appears probable that this is the usual occurrence in nature. 
List III (p. 63) is likewise very striking. It includes all the 
species (26) of which the males are still unknown. With the exception 
of three species (bicornis, stilesi and australiensis), all of the females 
have been found solely on birds, burrowing or nesting hosts, and bats. 
Of I. bicornis only three females are known; they were found on 
as many hosts. Ixodes stilesi has only been found once, and all the 
specimens (14 females) were found upon a single host. Ixodes austra¬ 
liensis was found once on a dog ( + ), and once on the marsupial rat- 
kangaroo (0). It is true that many of the species are represented only 
by one or two females, or by few specimens, and consequently there 
may be an error in certain cases in attaching much importance to the 
character of the type host—nevertheless, there is a very remarkable 
co-relation between the absence of males on the host and the life habits 
of the host. 
1 See Note on p. 67. 
