HABITS AND PECULIARITIES OF SOME SOUTH AFRICAN TICKS. 285 
mally only one visit to the host is paid in each of the three stages, and 
the visit is always one of several days’ duration, the body meanwhile 
becoming slowly distended. Some species drop to the ground to pass the 
quiescent periods preceding the moults, whilst others remain aflixed to: 
the skin of the host during one or both of these periods. It is stated in 
some writings that ticks subsist in part on vegetable matter. I have: 
no doubt that they derive their nutrition exclusively from living animals, 
despite the protracted periods that they often have to await hosts. 
Unfed larve and nymphs and adults that normally moult off the host will 
retain their vitality for many months when kept in clean, cork-stoppered 
bottles: this is a general characteristic, Oviposition occurs oniy once. 
It normally takes place in the soil or amongst matted vegetation or 
rubbish affording concealment on the surface. The process is always a 
slow one, and occupies from a few days to several months. The eggs 
number thousands, and the female dies beside them soon after she ceases 
to oviposit. The larve ascend vegetation, or anything extending above 
them, and come to rest generally at the top of some projection. There 
they may wait for months before an animal by rubbing against their 
support arouses them toactivity. The nymphs and adults of some species 
also lie in wait on vegetation, and depend on the passing of &n animal to 
brush them off ; but those of some other species hide in the ground aiid 
scramble to animals that wander near them. Both sexes attach to the 
host and take nourishment in all three stages. They appear inseparable 
as larve and nymphs, but are easily distinguished by secondary characters 
when the adult stage is reached. Mating appears to normally take place 
on the host, and it is usual to find the male affixed to the skin with his 
ventrum opposed to the ventrum of the female. The males generally, but 
not always, seek the females. The sexes are produced in about equal 
numbers ; but the adult male generally remains far longer on the host 
than the adult female, and hence is apparently the more numerous. The 
duration of the life-cycle is very indefinite owing to the prolonged periods 
which may be passed in waiting for hosts. It is also greatly influenced 
by the temperature. The development, as a rule, is most rapid with the 
temperature between 90° and 100° F. Most species delight in slightly 
humid surroundings, but some flourish where others would quickly perish 
by desiccation, 
The genus [xodes is placed first in Neumann’s classification of the 
Ixodine. The only South African species appears to be Jxodes pilosus. 
_ This species has been found in grass districts of all the colonies, but is 
usually uncommon. We have had great difliculty in rearing it, and have 
only succeeded when we have kept the surroundings in which the specimens 
were undergoing their metamorphoses excessively humid. The necessary 
condition is naturally found amongst rank vegetation on ill-drained flat. 
ground and in ravines, and it is on animals frequenting such situations. 
that specimens of the tick are generally found. The species in all of its 
stages seems a general feeder on warm-blooded animals, and to thrive 
best on the ox, sheep, and goat. The adult has been taken from the 
horse, mule, ox, goat, sheep, dog, hog, cat, leopard, bushbuck, and man,. 
and both larve and nymphs from the first six and man. All stages are: 
partial to the head, and particularly to the ears, but may be found almost: 
everywhere about the body. For convenience we term the period from 
the dropping of the female to the hatching of the eggs the ‘adult-larva 
stage,’ the period from the dropping of the larva to the appearance of the- 
