﻿OBSERVATIONS UPON GLOSSINA PALPALIS. 67 



Fly removed to a box at the temperature of the external air (35° C), he was, 

 however, dead. 



In this experiment a fatal result was only produced after an hour's exposure to 

 a temperature of 40°-41° C. This result should be contrasted with that pro- 

 duced by direct sunlight. In other experiments at this temperature, when the 

 flies were removed from the jars immediately they fell "as if dead," partial 

 recovery took place, but in no case was it complete. It was noticed in one case 

 that the right foreleg remained useless and bent up under the thorax. 



(b.) In the presence of ivater. 

 In the presence of water the effects of a temperature of 40° C. are perhaps a 

 little less severely felt than in its absence, as in one experiment of this nature a 

 male G. palpalis was not reduced to a condition of complete immobility by one 

 hour's exposure. On removal to a box at the temperature of the external air he 

 made but a slight recovery, and died within three hours. In another experiment 

 carried out under the same conditions 40 minutea' exposure to T. 40°-41°C. 

 proved fatal, so that the difference if it exists is a small one. 



(c.) Higher temperatures. 

 Temperatures higher than those employed in the foregoing experiments 

 (40 C -41°C.) are, however, rapidly fatal. The following experiment may be com- 

 pared with experiment No. 7, which was carried out under similar conditions. In 

 the latter all movements of the fly ceased, and death ensued after 60 minutes' 

 exposure to T. 40 c -41° C. (104 o -105'8° F.), in the former death resulted after 

 only 22 minutes at T. 43°-44°C. (109'4 o -lll-2° F.). 



No. 8. — Male G. palpalis in glass jar shaded from direct sunlight. No water 

 present in the jar, but only a few twigs. Degree of humidity of the 

 atmosphere — 27. 



C. Fly introduced. Very active. 

 Fly taking short flights. 

 Fly on his back ; got up again. 

 Fly on the floor. 



Fly on his back ; struggled up again. 

 Fly on his back, unable to rise. 

 Slight movements. 



Do. 

 Movements scarcely perceptible. 

 Do. do. 



Do. do. 



Slight movements on shaking the jar. 

 No movements observed. 

 Fly removed to a box at the temperature of the external air (34° C). Died. 



Conclusions. 



1. Glossina palpalis is able to withstand a lowering of the temperature to 



10°-7° C. 



2. Direct sunlight is rapidly fatal to G. palpalis. 



23527 E 2 



2.16 p.m. 



T. 44° ( 



2.17 



— 



2.18 



T. 43 



2.20 



T. 43 



2.22 



T. 43-2 



2.24 



T. 43-5 



2.26 



T. 43-5 



2.28 



T. 43-5 



2.30 



T. 43-5 



2.32 



T. 44 



2.34 



T. 43*8 



2.36 



T. 43-8 



2.38 



T. 43-8 



