GLOSSINA MORSITANS: REPRODUCTION 399 



running water, where the degree of humidity is constantly high, and to 

 the dense shade of forest trees, morsitans frequents less densely wooded 

 country, and, though it occurs near water, is not nearly so closely asso- 

 ciated with it. The type of country which it inhabits is denned by 

 Neave as ' a combination of the presence of such vegetation as will 

 ' provide moderate but not excessive cover, coupled with a hot and 

 ' moderately or even dry climate. ' Such conditions are to be found 

 in thick scrub and brush, near isolated clumps of trees and thickets with 

 dense undergrowth, rather than in the dense forests along the banks of 

 the great rivers. It is found at a much higher elevation than is the case 

 with palpalis, having been recorded at an altitude of 5,000 to 5,500 ft. 

 on the Congo-Zambesi watershed. 



In suitable localities the fly often occurs in enormous numbers, swarms 

 of them attacking travellers and their animals. Like the others of the 

 genus, it bites most actively in warm sunny weather, and is seldom seen 

 on dull and cool days ; the older travellers used to take advantage of its 

 diurnal habits and to attempt to pass through the fly belts with their 

 animals during the night. At times, however, it will bite at night, 

 especially in moonlight and when the weather is warm. Almost any 

 large animal will serve as host, and among them, of course, man, though 

 this species does not appear to exhibit the predeliction for human blood 

 which has been noticed in the case of palpalis. There is some reason to 

 believe that the buffalo, in the days before it was decimated and dispersed 

 by rinderpest, when it was the most numerous of the larger mammals, 

 was the main food of the fly. The alteration in the distribution of the 

 fly, and its disappearance from, and reappearance in, certain localities in 

 South Africa, is attributed to the scattering of the game. 



Until recently very little was known about the reproduction of this 

 species, or regarding the places in which its puparia were to be found. 



One was discovered in 1910 by Mr. Tack between the 



, ..._,, _,, Reproduction 



roots of a tree on the bank of a river in Southern Rhod- 

 esia, and until the present year his find remained the only record. The 

 Luanga Sleeping Sickness Commission, reference to the work of which 

 has already been made in connection with their demonstration of the 

 transmission of T. rhodesiense by means of this species, were more 

 successful, and Lloyd, the entomologist to the Commission, records 

 the finding of numerous puparia. The situations in which they were 

 found emphasize the difference in the localities chosen by this 

 fly and palpalis, and also suggest that the larva is possessed of very 

 considerable powers of locomotion. Of the nineteen localities which are 



