632 Recent Literature. [June, 
in an instructive manner the relations of the cesophagus to the 
mouth and proboscis. 
It appears that complicated as are the mouth-parts of the Dip- 
tera, the mandibles are least developed, or most often absent. 
They are present in the female Culex, but are absent in Eristalis, 
Bombylius, Musca and many other Diptera. 
The maxillz are, next to the mandibles, the’ oftenest absent in 
Diptera, but the maxillary palpi are usually, probably always, . 
present. The labium is the most fully developed part of the 
mouth, the large fleshy lobes so well developed in the house fly 
being termed the /abel/z. It appears that the mouth-parts arè 
most developed in the mosquito, which for this and other reasons 
stands at the head of the Diptera. a 
s to the poisonous nature of the mosquito’s bite Dr. Dim- 
mock’s views may be considered as most probably correct. He 
says: “ After having experimented a large number of times wi 
the living mosquito, I am convinced that there is use made ol a 
poisonous saliva. * * * When the insect is allowed to draw 
its fill on the back of my hand, the subsequent swelling 
from forty to forty-eight hours, and the amount of poisonous 
effect upon me, as proved by numerous experiments, 1$ ™ 
direct proportion to the length of time which the Culex has oc- 
cupied in actually drawing blood. The above-mentioned facts 
would indicate a constant outpouring of some sort of poisonous 
fluid during the blood-sucking process, and wouid necessi 
tube or channel for its conduction. Now, no other channel: ae 
through which saliva could pass from the base to the tip 1n shad 
mouth-parts which Culex inserts in the skin, and this, toge 
with the position occupied by the salivary duct in other Dipti, 
leads me to believe, without as yet being able to give anatomical ia 
proof of it, that the hypopharynx of Culex contain 4 duct 
pours out its poisonous saliva.” Biy is 
Dr. Meinert’s memoir is very well illustrated ; it 15 10 destlibe 
with a brief Latin synopsis. His work, while exact in pee phic 
tion of actual parts, appears to us to be lacking 1n aig gen- 
breadth. For instance, he has some singular views as to a, He 
eral homologies of the trophi of insects, especially D P calpella 
uses Kirby and Spence’s terms cu/tellus for mandibles an 3 ophi d 
for the maxillæ of Diptera. But his illustrations of the trof L 
numerous Diptera are made with great apparent care an 4 
ness, : though A 
Becher’s work is not so well illustrated as the foregoing, of each 
the number of genera represented is greater, a° type are rather 
dipterous family are represented; the descriptions of the flea 
rief, None of the authors compare the mouth-par's © gerlip of 
with those of other Diptera, Becher only figuring the te : 
Pulex. Dr 
The latest article is a short preliminary one by “™ 
