CERATOPOGON 221 



horrible means are grouped under one genus and 

 called the Ceratopogon, and comprise one hundred 

 AND ELEVEN described species. The sucking habit, 

 misogynists will learn with satisfaction, is almost 

 universally confined to the females. As a rule, the 

 larvas of the naked-winged forms of this genus are 

 aquatic, being laid in star-shaped clusters of algse 

 containing from one hundred to one hundred and 

 fifty eggs. The larvae of these species are worm-like 

 creatures which lie always on the surface of the 

 water. No prolegs appear on the prothoracic 

 segment, and they wriggle through the water like 

 minute eels. The pupa is shorter than the larva, 

 possesses conspicuous respiratory horns on the 

 thorax, is brownish in colour, and also remains on 

 the surface. If, therefore, care be taken to remove 

 stagnant water from the vicinity of the dwelling- 

 house, and sprinkle paraffin into the tanks and 

 uncovered water receptacles, much may be done 

 to decrease the appalling pest which mosquitoes and 

 their numerous allied forms constitute to dwellers 

 in tropical Africa. 



Then there are those dreadful forms of Glossina 

 the Tse-tse fly (6r. morsitans), and the G. palpalis, 

 to which latter has been traced the germ of the 

 dreaded sleeping-sickness now, it is said, gradually 

 approaching Lake Nyasa from the northward. In 

 the former type, the life history differs greatly from 

 that of nearly all the varieties of the Muscidae ; 

 thus, instead of depositing its eggs in horse or cow 

 dung, the female Tse-tse produces one single larva 

 at a time, which is nourished in the oviduct of the 

 mother until full-grown. On extrusion it turns at 



