HABITS AND PECULIARITIES OF SOME SOUTH AFRICAN TICKS. 289 
the neck. Both moults take place off the host. The adult-larva stage 
has been as short as twenty-nine days at midsummer ; and midwinter- 
laid eggs have hatched within 100 days at the office. The larva and 
nymph, as a rule, distend and fall after a visit of forty-seven to seventy 
hours, and the adult female generally remains eight to ten days. The 
male may remain ten weeks or more. The larva-nymph period may be 
only ten to twelve days at midsummer, and the nymph-adult period only 
eighteen days; in the incubator the nymph-adult period has varied 
from fourteen to eighteen days. The sexes attach independently, and 
after about three days the males detach and search for mates. The female 
distends, whether fertilised or not ; but the eggs of the few unfertilised 
ones observed have failed to hatch. The male, at least, is quick to detach 
from a host that dies. All stages await in some elevated position for 
some animal to brush them off in passing. Unfed adults have lived over 
seven months in a tube. There are probably two or three generations in 
a year under favourable conditions, 
Since Neumann wrote his monograph he has decided that the genus 
Rhipicephalus should be divided into two sub-genera, Eurhipicephalus 
and Boophilus. Eurhipicephalus contains several South African species 
that resemble one another so closely in their structural characters that it is 
difficult to distinguish them, especially in the larval and nymphal stages, 
The specific identity of some forms that we have attempted to study is in 
doubt. One undetermined species feeds in all its stages on hares, and 
appears as common in the dry Karroo as in coastal districts. Any dis- 
cussion of structural characters is avoided in these notes ; but, owing to 
ignorance of the fact being a source of error to systematists, it seems 
desirable to mention that adult Rhipicephalus males, during their stay on 
the host, change somewhat more in appearance than the adult males of 
other genera. By the gradual distension of the body the lateral and 
posterior margins are made to project more or less beyond the dorsal 
shield. Moreover, the males of most species of Hurhipicephalus protrude 
a prominent caudal appendage as they distend, the presence of which can 
scarcely be detected in specimens which have not fed for many days. 
The males of the three species of Boophilus which we recognise in South 
Africa have all a well-developed caudal appendage as soon as they assume 
the adult form. 
Eurhipicephalus appendiculatus appears to be a general feeder on 
warm-blooded animals. The adult, we know, readily attacks the ox, 
horse, mule, sheep, goat, dog, rabbit, and man ; we have not tried any 
stage on birds of any kind. The larva and nymph attach almost any- 
where on the skin: the adult shows remarkable partiality for the hairy 
margin of the ear, but we find that it will attach and develop quite as well 
on the scrotum. The. adult-larva stage has taken only thirty-nine days in 
the incubator, and from forty-five to eighty-six days at ordinary tempera- 
ture. Both moults are passed off the host. The larva and nymph may 
both become full-fed in three days, but usually take five or more. The 
adult female may feed up in four days, but usually takes at least eight. 
The larva-nymph stage has taken only ten days in the incubator, twenty- 
one at office temperature in summer, and forty-one to forty-four at office 
temperature in winter. The nymph-adult has taken eleven days or more 
in the incubator, and thirty-one to 100 at office temperature. The species 
leaves the host at death. Some half-fed nymphs which left a dead ox 
eae their vitality in a corked tube for over seven months. Unfed 
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