46 The Philippine Journal of Science isis 



contamination and the condensation of the moisture in the air 

 in the bottle, when kept at a temperature of from 20° to 28° C. 

 The excess of moisture causes the flies to become stuck by their 

 wings to the sides of the bottle where they soon die. 



The use of individual glass tubes. — This method has proved 

 the most successful for keeping Stomoxys in captivity. The fly 

 can be observed at all times, and its longevity is increased to 

 nearly the normal. Ninety-four days was found to be the 

 maximum life of adult flies kept individually in glass tubes. A 

 test tube of 24-millimeter bore, plugged with cotton, was found 

 the most convenient sort. A piece of white filter paper con- 

 forming to the size of the tube was found ideal to regulate the 

 moisture, and this was changed at least every two to three days. 

 It was found advantageous to change the fly to a fresh tube 

 not oftener than twice each week. In feeding it was not found 

 necessary to screen the mouth of the tube. The filter paper was 

 first removed, the base of the tube was directed toward the 

 window light and the tube was inverted immediately over the 

 animal's body. The fly after feeding was induced to release its 

 hold upon the skin of its host by gently tapping the tube and 

 gradually inclining the latter toward the light, after which the 

 filter paper was restored and the tube stopped with a cotton plug. 



The flies when not fed were kept in the dark at a temperature 

 betAveen 20° and 28° C. 



METHOD OF APPLYNG THE FLIES TO THE HOST IN FEEDING 



Monkeys. — The following method was pursued in applying 

 large numbers of flies in a bottle. The monkey was strapped, 

 abdomen down, to an improvised stock by means of surgical 

 gauze or twine. The wrists and ankles, which were bandaged 

 previously to prevent chafing, were first secured ; then the tail 

 was closely cropped, bound to a stout wire with straps of gauze, 

 and thrust into a narrow-necked bottle which contained the 

 flies to be fed. The other end of the wire was kept at a conven- 

 ient distance from the mouth of the bottle to facilitate manipu- 

 lation. Wiring the tail was necessary to prevent the animal 

 from switching that appendage against the glass and crushing 

 numerous flies. 



In feeding the flies from test tubes, the tubes were inverted 

 over the thigh or other convenient part of the monkey. At least 

 2 flies could be fed at once in this manner. 



Guinea pigs. — When this animal was subjected to fly bites in 

 a large museum jar it was found to be of advantage to im- 



