HABITS AND PECULIARITIES OF SOME SOUTH AFRICAN TICKS. 283 
the experiments, the habits and life-cycles of a number of species of ticks 
have been studied. It has been found that the habits are remarkably 
variable in some respects that have important bearing in the transmission 
of diseases, and on the choice or application of measures for the suppres- 
sion of particular species ; and therefore it is thought that the following 
compilation of notes on the habits and peculiarities of the species which 
have come under notice will not be without value. A discussion of the 
transmission of the diseases pertains more to the pathological section of 
this Association than to the zoological, and is reserved for a separate 
paper. The specific names used throughout these notes, except in treat- 
ing of the genus Boophilus, are based on determinations made by Neu- 
mann. 
Neumann divided the Zxodide into two sub-families, Argasine and 
Ixodine. Only two genera of Argasine are recognised, and representa- 
tives of both are found in Cape Colony. Argas persicus is a very common 
pest of fowls. Argas vespertilionis has been found a few times in places fre- 
quented by bats. Onithodoros savignyi var. cecus is reported from several 
dry districts of the Cape and neighbouring colonies, and O. talaje var. 
capensis is found in the nests of penguins on the west coast of the Cape, 
and also at Tristan de Cunha. 
Only Argas persicus has been closely studied. It is pre-eminently a 
pest of fowls, but it also common!y attacks geese, ducks, and turkeys, and 
has been reported to attack canaries and ostriches and man. By tests it 
has been determined that it will feed on pigeons, but I have not often 
found it associated with these birds. Both sexes moult the skin three 
times before becoming adult, and, as with all other ticks studied, the 
‘sexes have not been distinguished until the final moult. The eggs are 
laid loosely in crevices. The largest number laid at one time by a female 
under observation was 120. The hexapod larva crawls to a host, affixes 
itself, and remains attached five days or longer. The body meanwhile 
distends with blood, and towards the last undergoes a change in form, 
which gives the larval tick the general appearance of the later stages ; 
before this the resemblance is remote. When fully fed, the larva crawls 
away and secretes itself in any convenient shelter preparatory to moult- 
ing. In all its subsequent stages the tick normally visits its host in 
darkness, and usually remains only half an hour to two hours ; it dis- 
tends itself with blood in this short time and then retreats to a hiding- 
lace. 
: One visit suffices for each life-stage until the. tick becomes adult, and 
then it alternates its visits with oviposition. Some specimens under 
observation were fed six times as adults. Thus, during the life-cycle, 
there is one feeding by the larva or first stage,,one by the second stage, 
one by the third, and an undetermined number which may be more than 
six by the fourth or adult stage. The minimum interval between the 
visits varies with the season. In summer the second stage is ready to 
feed ten days after the larva quits the host, the third stage after a 
further period of two weeks, and the fourth after about three weeks more; 
the adults may feed about once a month at this season. During the cooler 
half of the year all stages are sluggish, and may not once seek a host. 
The length of time during which specimens may go entirely without food 
is remarkable. Adults have survived a year’s confinement in cardboard 
gan in my office desk, and under more natural conditions they take 
ar longer to starve to death, An infested disused fowl-hause has been 
