December, '22] Richardson : house fly and carbon dioxide 427 



carbonate) or 50cc. of a saturated solution of ammonium carbonate. 

 The solid ammonium carbonate (in liunps) was always covered with a 

 thin layer of bran. Unless ammonium carbonate solution was used 

 from 25 to 50cc. water were added to each dish. The funnel experiments 

 with ammonium carbonate were similar to the carbon dioxide experi- 

 ments in general arrangement except that a piece of wet cotton covered 

 the porcelain disk over which the bran was spread. The funnels were 

 supported by means of rubber stoppers in bottles which contained 

 water. Other details are given in table II. 



The controls contained only bran and water; in arrangement and 

 amounts of these substances they followed closely the other experi- 

 ments. 



The following experiments are selected to illustrate the methods 

 and results obtained. 



Table 1. Carbon Dioxide and Ammonium Carbonate Experiments in Porcelain Dishes 

 Carbon Dioxide Experiments: Generators contained 50 g. Na^COa and 30cc. HaO; dropping 



funnels held 150 cc. 20 volume % HjS04; each dish contained a piece of cotton, 10 g. bran moistened 



with HaO and 25 to 50 cc. HjO. 



Ammoniltm Carbonate Experiments: Each dish contained cotton, 25 to 30 g. solid ammonium 



carbonate, 10 g. bran moistened with HaO and 25 to 50 cc. HaO. 



Controls: Each dish contained cotton, 10 g. bran moistened with HaO and 25 to 50 cc. HaO. 



Duration Eggs deposited: 



No. Material Date Hrs. Mins. Egg masses* Single eggs Total eggs 



1, 4 COa 7-23 6 45 _ - 



2 Ammonium carbonate " " " 



3 Control " .... 

 5, 7, 9 COa 7-24 11 

 6 Control " " " 

 8 Ammonium carbonate " " " 

 10, 12, 14 COa 7-25 8 30 

 11 Ammonium carbonate " " " 

 13 Control 



15 Control 7-26 9 45 



16, 17, 19 COa 



18 Ammonium carbonate " " " 



20, 21, 23 COa 7-27 10 



22 Control 



24 Ammonium carbonate " " " 



25 Ammonium carbonate 7-29 10 20 

 26, 28, 29 COa 

 27 Control 



*An egg cluster containing 2 or more eggs was considered to be an egg mass. 



Table 2. Carbon Dioxide and Ammonium Carbonate Experiments in Glass Funnels 



Carbon Dioxide Experiments: Generators contained 100 g. NaaCOj and 60 cc. HaO; dropping 

 funnels held 300 cc. 20% acid; each funnel contained 15 g. moistened with HaO. 



Ammonium Carbonate Experiments: Each funnel contained a piece of cotton, 15 g. bran moist- 

 ened with HaO and 25 g. solid ammonium carbonate. The funnels were supported by means of stop- 

 pers in 400 cc. bottles containing 300 cc. HaO. 



Controls: Each funnel contained 15 g. bran moistened with HaO and was placed in a 400 cc. bottle 

 which held 300 cc. HaO. 



Dnrat.inn Effffs denosited: 



Total 

 

 

 144 

 54 

 

 

 

 

 

 

 



