1880.] Dr. G. Thin. On Bacterium foetidum. 



477 



or free in the fluid. In many of the long rods segmentation of the 

 protoplasm, by which rod-shaped masses of equal length were formed, 

 was observed, the delicate tube wall being continued from one segment 

 to the other unbroken. The observations were not sufficiently ex- 

 tended to determine whether the bacterium forms spores when culti- 

 vated in turnip infusion, but they suffice to show that if it does occur, 

 it occurs much less actively than when the cultivation is in vitreous 

 humour. 



That the foetid odour of the stocking is due to the development of 

 the bacterium was shown by the characteristic fcetor being repro- 

 duced in the cultivation glasses, although the strength of the odour 

 diminished in successive generations. The fluid of the fourth genera- 

 tion still smelt powerfully, and was at once recognised by several 

 persons who had smelt the original piece of stocking ; the fluid of the 

 eighth generation still had the characteristic smell, but had it so feebly 

 that although at once recognised by myself and the patient from 

 whom the stocking had been obtained, it was not considered distinctive 

 by a third person who had recognised the smell of the fourth genera- 

 tion. Mr. Lister, to whom I mentioned this fact, informs me, and 

 authorises me to state, that he has made an analogous experience with 

 the Bacterium lactis. This bacterium, after being cultivated in 

 successive generations in urine, although it still retains its capacity to 

 induce the lactic fermentation, possesses it in a less degree than when 

 it has been grown in milk, The vitreous humour in a similar way 

 would seem to be a less favourable medium for the Bacterium foetidum 

 (in so far as the production of the peculiar odour is concerned) than 

 in the mixture of sweat and serum in which it develops in the 

 stocking. 



EXPLANATION OF THE PLATE. 



[Figs. 1, 2, 4, 6, 7, 8, and 9 are camera drawings by Mr. Knowsley Thornton, made 

 by the use of an excellent immersion objective by R. and J Beck, and 

 I am much indebted to Mr. Thornton, not only for these careful and 

 accurate drawings, but for valuable suggestions bearing on the subject 

 of the paper. The magnifying power for these figures is 900 diameters. 



In fig. 3 are forms drawn by myself without the camera. They aff ord no guarantee 

 of size. 



In fig. 5, drawn by myself, are camera drawings, as regards length (magnifying 

 power 1,000 diameters), but they give no guarantee as regai'ds breadth.] 



Fig. 1. The micrococcus, from the sock uncultivated. All the other figures are 

 drawn from cultivated specimens. 



Fig. 2. Micrococcus forms in development, a and b show two phases of the same 

 object. 



Fig. 3. a. Further stages in the development of the micrococcus ; b., examples of 



spore appearances in rods. 

 Fig. 4. Elongating rods. 



Fig. 5. Elongated rods, three of them showing segmentation in the protoplasm. 

 Fig. 6. Segmented rods. 



