STAGES OF GLOSSINA MORSITANS, WESTW. 293 
Considerable irregularity has been displayed by the females in extruding 
larvae. After the first one had been born, many of them did not produce a second 
for a considerable length of time, and this may have been dependent upon the 
meteorological conditions to some extent. A number of the flies, however, have 
produced a second larva at an interval of from 14 to 15 days after the birth of 
the first, and this may be taken to represent the normal period of gestation 
under the laboratory conditions. 
At the completion of its intra-uterine life, the larva almost completely fills the 
abdomen of the mother, and can be made out through the parietes as a dull 
yellowish-white oval body, with the black tumid lips presenting. ‘These become 
a prominent feature several days before birth. The extrusion of the larva is 
accomplished very rapidly, and the maggot commences to crawl] about as soon 
as it is born. 
The only accident of gestation which has been seen is the abortion of various- 
sized larvae, and most of these mishaps occurred during two or three cold, 
cloudy days. Intra-uterine pupation, mentioned by Roubaud, has never been 
noticed. 
The Larva, 
The larva of Glossina morsitans resembles those of other species of the genus 
which have been described. 
Fig. 1.—Dorsal view of larva of Glossina morsitans, 
Westw., showing the tumid lips and antennae. x 10. 
It is a small, elongated maggot, characterised by the black tumid lips which 
spring from the last segment. The body is composed of twelve segments, and is 
widest and thickest at the junction of the posterior and middle thirds, whence it 
tapers more noticeably towards the pointed anterior end. The tumid lips are 
placed slightly dorsally and rather obliquely to the long axis of the body, so that 
they are directed backwards and upwards as the larva moves about. In colour 
it is a dull yellowish-white with a slightly dusky tinge, which becomes more 
