44 
Coimlation in Ticks 
We have dwelt thus at length upon the process of copulation in 
0. mouhata, because until now it has never been understood how the 
male impregnates the female. 
As bearing on the process of copulation in Ixodidae we would add 
the following remarks : 
We have stated elsewhere that the genus Ixodes (group Prostriata) 
is widely separated from the other genera of Ixodidae (group Meta- 
striata) in important points of anatomical structure. In Ixodes the anal 
grooves surround the anus in front, the sexes show marked dimorphism 
in respect to the structure of the hypostome, and in certain species the 
sexes are frequently found coupling upon the host. In Ixodes the male 
inserts his mouth-parts into the female sexual orifice as a part of the 
sexual act. In none of the Metastriata has a similar method of coupling 
been observed; here the males remain attached for longer periods to 
the host and they do not appear to wander about upon it as do some 
species of Ixodes whose males infest the host together with the females. 
In Metastriata the females and males are found attached to the host so 
that in many cases the venters of the sexes are apposed. 
We have discovered that in the Metastriata (including the genera 
Haemaphysalis, Dermacentor, Rhipicentor, Rhipicephalus, Boophiliis, 
Margaropus, Hyalomma, Amblyomma and Aponomma) all the males 
possess a chitinous apron or flap covering the sexual aperture. The 
apron arises from the integument anteriorly to the sexual aperture and 
is dii’ected backward over the aperture; it is frequently serrated along 
its rounded posterior border which is free. The apron can be readily 
lifted by inserting a flue needle between it and the body surface; it is 
very thin at the free margin, whereas it grows gradually thicker toward 
its origin. The apron is absent or rudimentary in the females. 
Now we find that in Ixodes the males do not show an apron, or it is 
very rudimentary in character. On the other hand the apron, though 
very thin, may be very well developed in the females; is best seen in 
young specimens. 
The presence of the apron in the males of Metastriata and its absence 
in Ixodes is very suggestive, and, taken together with the other dif¬ 
ferences, indicates that copulation may possibly take place in another 
manner in the Metastriata to what it does in Ixodes. The mechanism 
of copulation in Metastriata still remains to be determined and the 
significance of the apron requires to be explained. 
