516 MISS O. C. LODGE ON THE 



otlier traps. lu all cases but one, a luiicli L-vrger number of 

 females was caught. This is probably to be accounted for by the 

 fact that the substances used as baits served also for breeding- 

 materials. The following results were obtained : — - 



A. In the greenhouse. S ■ ? • 

 (rt) Flies caught in jar with wire-gauze fuiniel, baited with an eight 



days' old mixture of casein, water, and bread, 3-5 hours after 



Amyl acetate had been added, July 25, 1915 19 227 



(6) Flies caught in jar with wire gauze-funnel, baited with two 



daj's' old stout and sugar, Aug. 1, 1915 25 85 



(c) Flies caught on piece of banana, placed on shelf in sun. (Very 

 man3' flies came to feed, and many eggs were laid.) As many 

 as possible of the flies were caught 16 32 



B. In the "flj'-room." 



(a) Flies caught in balloon trap, set for \-\ hour over casein, brown 



sugar, banana, and water bait, Nov. 29, 1915 26 118 



(b) Ditto, Dec. 10, 1915 90 83 



{o) Ditto, Dec. 11, 1915 24 36 



{d) Ditto, Dec. 13, 1915 43 54 



(/) Ditto, for i hour, Dec. 15, 1915 86 108 



(^) Ditto, for 14 hours, Feb. 9, 1916 13 22 



(A) Ditto, for 1 hour, Feb. 9, 1916 31 43 



(i) Ditto, for 24 hours, Feb. 10, 1916 28 52 



Total 401 860 



(3) Counts were also made of the flies which died naturally, 

 which had been picked up in the " fly -room" in August and 

 September. The proportion of males and females was approxi- 

 mately equal. The numbers are given below : — 



S. ?. 



'(«) Dead flies picked up in fly-room on Aug. 28, 1915 122 99 



(6) Ditto, Aug. 20 to Sept. 2, 1915 132 143 



Total 254 242 



(4) Again, in the experiments where various poison-baits were 

 fed to house-flies enclosed in cylinders (Table 11.) only in 14 out 

 of 69 cases was the percentage of deaths among the females 

 higher than that of the males. 



List of Abbreviations. « 



Ale Alcohol (90 "n unless otherwise stated). 



Abs.Alc Absolute Alcohol. 



Adren.HCl Adrenalin hydrochloride, '01 % solution. 



Cafi". Cafleine. 



Dimethan Dimethylanilinc. 



Ethyl.SC.N Ethyl sulphocy anide. 



F Formalin. 



Meth.salic Methyl salicylate. 



Nic Nicotine. 



Potass. salic Potassium salicylate. 



Pyrid Pyridine. 



