° 284 REPORT-—1905, 
under observation for over three years. Larv:e were found in the crevices 
more than six months after the fowls had been removed, and adults 
were still present in numbers when the place was last searched, thirty- 
seven months, I believe, after the last opportunity any of them had to 
take food. The survivors were much shrivelled, but I believe most of 
them capable of continuing their fast until warm weather sets in again. 
The male is as large as the female at the time of the tinal moult, but does 
not afterwards increase appreciably in length or breadth, whereas the 
female increases in these dimensions with her first adult feeding. In their 
subsequent visits both sexes merely distend to the size attained at the 
first adult feeding. There is still some uncertainty in regard -to the copu- 
latory habits of ticks, so it is mentioned that the sexes of the fowl tick 
have been only thrice observed in connection. In all three cases the male 
had his rostrum inserted into the genital pore of the female, and both had 
fed within a few days. 
Only a few observations have been made on the habits of other 
Argasine, but it appears that Onithodoros savignyi var. cecus and O. 
talaje var. capensis both alternate short visits to the host with lengthy 
resting periods, It is said that a not uncommon prank amongst the 
Jabourers on the guano islands of the Cape Coast is for the older residents 
to annoy new-comers by infesting their sleeping places with O. capensis 
specimens, O. cecus also attacks man. It infests loose soil in the shade 
of trees and rocks in desert-like tracts, and attaches itself to animals 
which come there to rest. In some parts it infests native huts ; and the 
sites of villages are said to have been changed because of its presence. It 
may distend itself with blood in less than halfan hour. Unlike A. persicus, 
it will attack its victims in daylight. By experiment it has been found 
that men, goats, sheep, cattle, dogs, and fowls are all acceptable as hosts, 
The females alternate feasting with oviposition. At least three moultings 
of the skin occur before the adult stage is reached, and ouly one feeding 
intervenes between moults. The larva takes no food. Soon after hatch- 
ing it undergoes a moult, and becomes the octopod second-stage tick. 
Specimens in different stages of life have been kept without food in dry 
sand for upwards of a year. 
Acquired adaptation to the surroundings and to the habits of the 
usual hosts is most apparent in the structure and habits of A. persicus 
and QO. cecus. It seems not improbable that the Argasine are descen- 
dants from forms which remained for days at a time on the host, for 
witness the lengthy feeding period of the larva of A. persicus. Were the 
larger later stages to remain, they would be in great danger of being 
found and devoured by the fowls. Again, the larva is plump and rounded 
until it is time for it to leave the host. Then it becomes flattened horizon- 
tally like the mature ticks. Were it toremain rounded, or were the later 
stages to have this shape, there would be difficulty in finding places in 
which to hide. All the stages of O. cecus are rounded, and such a shape is 
as good as any other for hiding in loose ground. Obviously, when this 
tick is on an animal in a desert place it is in danger of being carried away 
from localities where it has a chance of again finding a host, and hence the 
shorter its visit the greater its chance of surviving to come again. 
The Jxodine are also admirably adapted for the life they have to lead. 
All the species that we have reared moult twice, and the life-cycle is 
thus divided into three active stages—the larval, nymphal, and adult. 
The larve are all hexapod, and the nymphs and adults octopod. Nor- 
