DIPTERA. Be pe) | 
profound knowledge of these transformations, and an expla- 
nation of the changes which take place in the female at the 
moment of depositing her larve. The latter, in particular, 
has surpassed his predecessors by anatomical investigations 
which have unveiled some highly interesting and curious 
facts, such as the existence of salivary glands, of a sort of 
matrix(1) consisting of a large, musculo-membranous pouch 
adapted for gestation and analogous to the uterus of woman, 
and of ovaries entirely different from those of other Insects. 
These ovaries consist of two obtuse, ovoid bodies filled with 
a white homogeneous pulp, free and rounded at one extremity 
and terminating at the other in a peculiar duct. According 
to this anatomist these ovaries closely approximate to those of 
woman in their form and position; Reaumur had a glimpse 
of them. The matrix, which at first is very small, by the 
progress of gestation becomes enormously dilated, pushes 
back the viscera, and finally invades the whole cavity of the 
abdomen, which is thus rendered very large. ‘The memoir 
of this able observer presents other interesting facts, which, 
as they differ but little, if at all, from the ordinary laws, we 
shall not stop to analyze. 
These Insects, which have been called by some authors 
Mouches-Araignees, live exclusively on Quadrupeds or Birds, 
run very fast, and frequently sideways. 
Some—Coriaces, Lat.—(2) have a very distinct head ar- 
ticulated with the anterior extremity of the thorax. ‘They 
form the genus 
Hiprososca, Lin. Fab. 
(1) Professor Nitzsch, who in his Memoir on Epizoic Insects treats of various 
genera of Pupipara, mentions two ovaries and four biliary vessels in Hippobosca, 
but he neither alludes to this matrix nor to the salivary glands. 
(2) Doctor Leach has published a Monograph of these Insects, enriched with 
excellent figures, beautifully engraved. 
Vout. I1V.—2 Q 
