346 
Ornithodorus moubata 
the sexual orifice is situated ventrally between the first pair of coxae about 
midway along their length. The orifice is surrounded by lip-like folds, the 
anterior lip being concave posteriorly and the posterior lip almost rectilinear. 
The anterior lip is more highly chitinized than the posterior one. A tongue¬ 
like flap arises from beneath the posterior lip and protects the aperture which 
lies between its anterior portion and the concave margin of the anterior lip. 
The female genital aperture (Fig. 5 B) or vulva, is readily distinguishable, 
being broad, slit-like, and situated more posteriorly than the male orifice. 
The vulva lies ventrally in a transverse oval depression of the integument, 
situated between the posterior angles of the first pair of coxae. The lips of 
the vulva protrude more or less from the oval depression and are comparable 
to the lips of the human mouth. The anterior lip is rectilinear on its anterior 
margin, the posterior lip, with which it is continuous, being concave anteriorly 
and at the sides where it joins the anterior lip. Protruding in a tongue-like 
manner from between the lips is a chitinous fold, comparable to the structure 
seen in the male, and having a concave anterior margin. The female orifice 
lies between this fold and the anterior lip. In females that are ovipositing 
the vulva may be situated more anteriorly than here described. 
In the last stage nymjphs , from which the adults emerge, there is always 
an Anlage or pit situated at the point where the genital orifice of the adult 
occurs. This pit may be sufficiently deep to mislead the observer into be¬ 
lieving that he is dealing with an adult specimen 1 . The Anlage, which is 
absent in younger stage nymphs, does not however show the structure which 
is typical of the adult. 
Summary of Eesults. 
1. Copulation between individuals of the two species 0. moubata and 
0. savignyi may occur, and the stimulus of coition may induce oviposition, 
the eggs being non-fertile. 
2. There is no evidence of parthenogenesis in this species, nor do these 
ticks undergo ecdysis after reaching maturity. 
3. An increase in temperature of 8° C. from 22° C. (a) doubles the rate 
of oviposition, ( b ) decreases the fertility of the eggs by 30 per cent., ( c ) reduces 
the longevity of the female tick from 715 to 397 days, i.e. by 40 per cent, and 
( d) approximately halves the period required for metamorphosis, under 
laboratory conditions. Under these conditions at 37° C., reproduction is 
inhibited, and the longevity of the female is reduced by 80 per cent. 
4. An individual may undergo from four to eight ecdyses before reaching 
maturity, the great majority of the males appearing after the fifth ecdysis 
and the females about equally after the fifth and sixth ecdyses. 
5. Engorgement can take place one or two days after emergence, at any 
stage, the average time required being three-quarters of an hour. There is 
1 The statement by Donitz (1907) that adult moubata may moult is contrary to our experi¬ 
ence and is doubtless due to his taking last stage nymphs for adults. 
