1899] MICROSCOPICAL JOURNAL. 263 



Experiments in Feeding Some Insects with Cultures of 

 Comma or Cholera Bacilli. 



R. L- MADDOX, M. D. 



On looking over some old slides lately a few were found 

 that related to the results obtained by experiments,made 

 at two different periods in the year 1885, on feeding flies 

 and other insects with cultures of living comma or 

 cholera bacilli. Some of the mounts had been spoiled, 

 being overrun by mycelial thread, the specimens having 

 been mounted dry. Some of the specimens had been 

 lightly stained, others were unstained. As none were 

 figured or photographed, it occurred to me that three or 

 four, if reproduced, might yet be of interest, if they 

 were utilized to illustrate a very brief resume of the two 

 articles published in the numbers for August and Decem- 

 ber of the Royal Microscopical Journal of the same year. 

 Consequently four of the slides have been selected to il- 

 lustrate by photomicrographs the following remarks : 



The object with which the experiments were under- 

 taken was firstly to ascertain if the comma bacillus was 

 pathogenic to insects when fed in ordinary or diluted cul- 

 tures on sugar ; secondly, to note if the dejecta contain- 

 ed any of the bacilli in a living state ; and thirdly,to find 

 out if cultures could be made from such excreta. 



Of course it was necessary to see microscopically if the 

 ordinary dejections contained any curved bacilli. This 

 was done by retaining such insects in captivity for some 

 time before being fed with the cultures. These cultures, 

 which were originally in agar-agar and gelatine media, 

 had been very kindly given to me by Prof. E. Klein, F. 

 R. S. Wasps, bees, Eristalis , the black beetle and the 

 common blue-bottle were chiefly used in the experiments. 

 The bee had to be discarded, as curved bacilli had been 

 found in it by Mr. Cheshire, though I had not noticed any 

 in the evacuations. One wasp was retained in captivity 



