3i3 
(2) The two fang-like cheliceres lying loosely 
each in a sheath above the horizontal plate and nearly 
filling the upper cavity of the rostrum. 
(3) A triradiate pumping organ (pharynx) lying 
below the horizontal plate and occupying, with its 
muscles, the lower cavity of the rostrum. 
(B) Eurhipicephalus 
The Gorged Female. —Obtain a large gravid female 
and remove the dorsal chitin, as in Ornithodoros , but 
avoid cutting through the rostrum. Observe that, in 
the main, the organs are similar to those of Ornithodoros , 
but that the following differences are present (Fig. 
101) :— 
(a) The system of diverticula is simpler, and 
there are no anterior branches. 
( b ) The ovary is much longer and thinner, and 
the spermatheca relatively much smaller. 
( c ) The salivary acini are much more loosely 
packed so that the organ, as a whole, is less easily 
differentiated. 
(d) The cephalic gland consists of a number of 
long finger-like projections. 
(e) There are large dermal glands lying among 
the fat and tracheal tissue. 
The Ungorged Female. —Place on a slide and with 
a sharp knife bisect the tick along the middle line. 
Place one of the halves in a drop of saline, and fixing the 
extreme outer edge by means of a needle, scoop out 
the whole of the contents with a scalpel, disturbing 
the arrangement of the tissues as little as possible. 
Under a lens most of the viscera are readily isolated and 
can be removed for study to another drop of saline. 
