262 W. A. LAMBORN. 



The results of these experiments are given in the following table : — 



Flies released at Lipimbi R. 



Flies recaptured at Liiigadzi. 



Date. 



No. of flies, 

 aU males. 



Date. 



No. of flies 

 recaptured. 



3.ii.l5 



4.ii.l5 



5.ii.l5 



6.ii.l5 



7.ii.l5 



S.ii.lS 



10.ii.l5 



ll.ii.l5 



12.ii.l5 



13.ii.l5 



15.ii.l5 



16.ii.l5 





. 



146 

 129 

 231 

 111 

 142 

 121 

 130 

 183 

 163 

 116 

 118 

 186 



4.ii.l5 



5.ii.l5 



6.ii.l5 



7.ii.l5 



8.ii.l5 



10.ii.l5 



ll.ii.l5 



12.ii.l5 



13.ii.l5 



15.ii.l5 



16.ii.l5 



17.ii.l5 







3 

 1 

 1 

 2 

 1 

 1 

 1 

 2 

 1 

 2 

 1 

 1 



General Observations. 



T have repeatedly seen flies settled on wet sand, for the purpose I imagine of 

 drinking, though as the fine proboscis only is lowered while the palps remain in the 

 usual position in front of the head while the insect is feeding, and as it does not 

 permit one to approach very near, it has been impossible to settle the point. I have 

 endeavoured to study the matter further by starving flies in captivity, providing 

 them only with wet sand, but even though they survived longer than a similar 

 number kept entirely without water, I was not quite sure even then that they did 

 drink, though I thought I saw one or two do so. 



I have endeavoured to test also whether flies ever drink dew, and whether they 

 will feed on various fruit juices, saline solution, etc., but have not obtained any 

 positive results. 



Though there seems to be some evidence that the flies are attracted to a moving 

 object through the sense of sight, I have found repeatedly that if well starved flies 

 with one wing clipped are released in long grass, they will make their way by running 

 to a person sitting at a distance of ten to twelve feet, whom it is impossible for them 

 to have seen. The sense of smell therefore must play an important part in leading 

 them to their prey. But the smell of fresh blood does not have the effect of attracting 

 flies, for I smeared the blood of a freshly shot duiker antelope, and on another 

 occasion the blood of a fowl, on trees in the fly area and none came to it, though 

 there was a breeze blowing and a fair number of flies were in the neighbourhood. 



Conversely, flies with their antennae snipped off at the base with fine scissors, 

 which does not seem to make any material difference to their well being in captivity, 

 have been found in a few instances to make their way to a moving person from a 

 short distance, ten to fifteen yards. 



