1899] MICROSCOPICAL JOURNAL. 265 



to refer to. N. Davaine had also found that flies carry 

 the contagion of infected blood, consequently my experi- 

 ments only added another possibility to the list. I found 

 that Eristalis tenax supported captivity fairly well, and 

 as it breeds in sewers, I expected it might possess advan- 

 tages for these experiments ; but this was not the case, so 

 the common blue-bottle fly 'was selected as the best, and 

 the following remarks will apply chiefly to this insect. It 

 may however be stated that the natural dejections of the 

 Eristalis contained no curved rods, and after feeding on 

 the cultures, only very few were seen in the evacuations. 

 The cultures placed on aniline dyed sugar did not seem to 

 particularly affect them, except to increase the oily 

 globules in the stools. Some were allowed their liberty, 

 while others were killed to examine the perivisceral fluid, 

 when by staining many pale, motionless rod bacilli of four 

 or five joints were noted, also a few rather large rods,but 

 scarcely a curved bacillus could be found. 



A female blowfly placed in captivity was firstly fed 

 with sugar moistened with a watery solution of methyl 

 violet for six days, and then seemed extremely feeble. It 

 was then fed on sugar damped with a gelatine culture 

 which though much broken down, contained abundance of 

 commas, but fearing it might be unsuitable, I changed for 

 an agar-agar culture not broken down. The fly at first 

 fed freely on this, but later a male blowfly was also placed 

 under the same tumbler. Both, after feeding off and on 

 for six hours, furnished together six dejections. These, 

 though much dried, furnished well marked, double or S- 

 shaped bacilli, but without movement. The next day the 

 flies were seen in coitus, and'a little later the female was 

 found dead. In the perivisceral fluid scarcely a comma 

 could be found. The male was now kept by itself and 

 fed from the original agar-agar culture. The daily ex- 

 aminations of the dejections did not lead to much, until 

 about the seventh day a fair number of the crooked rods 



