950 Transactions of the Society. 



and althoTigli I, unfortunately, omitted to inoculate a gelatin tube 

 from the three patches of growths found on one of the slides, in 

 the so-called plate culture, the growths and organisms were so 

 distinct and characteristic of the comma bacillus, that the result 

 was deemed sufficient to establish identity. 



In conclusion it may perhaps be as well to offer some remarks 

 upon sundry points connected with these investigations. From the 

 appearance of the dejections and from watching the insects feeding, 

 the gelatin and agar-agar cultures seemed less suited for the ex- 

 periments than the more fluid media, as the meat infusion. The 

 flies seldom remained for any time sucking the sugar when the 

 agar-agar culture was used, and they would often turn the morsel 

 of sugar over in search of the moistest portions. The gelatin 

 cultures seemed to furnish very tenacious dejections, and possibly 

 these drying so hard, the bacilli had less chance for rejuvenescence. 

 In any future experiments I should suggest the use of fluid cul- 

 tivations. Care had to be used in damping the sugar or it sank 

 down into syrup ; if not moist enough there was a chance of the 

 material drying on it in a short time ; there was also the risk of 

 the organisms being left dry on the surface, the sugar acting as a 

 kind of filter. The number of the comma bacilli passed did not 

 appear to have any definite ratio to the number of dejections passed 

 in the twenty-four hours. The same diet after a few days seemed to 

 largely augment the number of oily granules, and these to precede 

 a period of debility. The watery evacuations, and the rapidity with 

 which they occurred, I could not distinctly refer to a large increase 

 in the numbers of the bacilli, though I cannot say they were not in 

 some way related. How far the action of the digestive juices may 

 have been detrimental to the microbes, or how far they may have 

 encouraged their growth, are uncertain points. I am rather in- 

 clined to believe they did to a certain extent hinder the rejuve- 

 nescence, and that they did not encourage the growth of the 

 organisms, though I have no absolute proof to offer. The shortest 

 period in which the curved bacilli were found in the dejections of 

 the fly, after feeding on the culture, was six hours, though they 

 may have been passed earlier. There was no reason in this in- 

 stance, in which the male fly was placed in the same tumbler as 

 the female, to suppose they existed in the natural excretion of the 

 male fly, as they had not been found in any of the numerous 

 examinations made of the ordinary dejections of the other flies. 

 The non-success in the inoculations was a great source of trouble, 

 and I feel pretty confident in the successful experiment ; had 1 

 trusted to the single inoculation it would most likely have resulted, 

 like so many others, in failure. 



If it be true, and these experiments seem to me conclusive, that 

 the curved bacilli can retain life in the intestines of the fly, we can 



