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black setze, which are greatly elongated at the base of the abdomen 
and the extremity and sides of each segment; the first segment is 
marked at each side close to the anterior angle with a round black 
spot, and each of the four following segments has a broad basal fascia 
of dark brown, interrupted in the middle. The sides and under sur- 
face of the thorax are varied with black patches; the abdomen is 
pale-coloured beneath, with a large terminal oval plate, down the 
middle of which runs a pale longitudinal line, preceded by two small 
oblique oval patches, thickly clothed with minute black setze. 
The peculiarities of the genus Glossina, whereby it is at once distin- 
guished from Stomowys, to which it is nearly allied, consist in the dilata- 
tion of the extremity of the discoidal cell, the rounded horny bulbous 
base of the proboscis, which is not angulated at its base, and the long 
and slender flattened palpi, which together form a sheath protecting 
the proboscis. Wiedemann’s typical species (which has remained 
unique to the present time), Glossina longipalpis, (subsequently de- 
scribed by Robineau Desvoidy under the name of Nemorhina pal- 
palis,) is a native of Sierra Leone, where it was collected by Afzelius. 
M. Macquart, judging from the structure of the mouth, considers it 
probable that it does not live upon the blood of animals, like Sto- 
moxys, but upon the nectar of flowers; the two setze which are en- 
closed in the proboscis and compose the sucker being so slender, that 
it is difficult to conceive that they can pierce the skin, the palpi being 
also elongated so as to form a protection to it, and thus further indi- 
cating its weakness. There is however so great a difference between 
the structure of the proboscis in these insects and Stomowys, that I do 
not doubt that they are able to pierce the skin of a horse, the proboscis 
of Glossina being a long, straight, horny, needle-like instrument, and 
not elbowed, with fleshy lips, as is that of Stomorys. Moreover, the 
bulbous dilated base of the proboscis must evidently play an import- 
ant part in the economy of the insect, either by giving additional 
support to the proboscis when in the act of piercing the skin, or by 
containing powerful muscles for the action of the enclosed sete ; or, 
as suggested to me by Prof. Owen, this dilated base may be analogous 
to the dilated base of the sting of the Scorpion, and like it contain a 
reservoir of some powerfully poisonous liquid. 
The account of the irritating powers of the Glossina given by Cap- 
tain Vardon is, it is true, not so detailed as could have been desired, 
but we learn sufficient to arrive at the conclusion that its effects are, 
to a certain extent, exactly like those of the Tabanide ; how far the 
attacks may be attended with tumours, similar to those produced by 
the Simulium, and whether a tropical climate may not extend the 
effects of the attack, producing inflammatory action upon animals 
perhaps never before in those latitudes, are questions which have yet 
to be answered. One thing however appears to me evident, that the 
Séts¢ is no other than the Zimb of Bruce, (an insect respecting whose 
real family and even existence so many doubts have been expressed, ) 
or at least that that insect is a larger species of Glossina, to whose 
real habits Bruce has added those of a species of @istrus. With the 
view of establishing this assertion, as well as of clearing up what I 
