STAGES OF GLOSSINA MORSITANS, WESTVV. 293 



Considerable irreguliirity has been displayed by the females in extruding 

 larvae. After tlie first one had been born, many of tliem 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 pei'iod 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 dui-ing two or three cold, 

 cloudy days. Intra-uterine pupation, mentioned by Roubaud, has never been 

 noticed. 



The Lanui. 



The larva of Ghis.nna morxitinis resembles those of other species of the genus 

 which liave been described. 



Fig. 1. — Dorsal view of larva of Glosaiua 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 tmnid 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 



