474 



Dr. G. Thin. On Bacterium foetidnm. [June 10, 



study more conveniently the different forms assumed by the organism 

 when under cultivation, it was grown for successive generations in 

 pure vitreous humour, contained in pure test glasses, and kept at 

 96° to 98° F. 



The glasses, fitted with glass caps, and covered by a larger protecting 

 glass, were placed on small glass squares and purified by being kept at 

 a temperature over 300° F. for about two hours. The flasks for the 

 vitreous humour' were protected by carbolised cotton wool and simi- 

 larly heated. The vitreous humour was obtained by collection from ox 

 and sheep's eyes. It was squeezed through fine muslin, and intro- 

 duced with proper precautions to a pure flask, which was then placed 

 for half an hour in boiling water. All the apparatus used and the 

 method of experimenting were modelled after those described by 

 Mr. Lister in a paper on the lactic fermentation in the twenty- ninth 

 volume of the " Transactions of the Pathological Society of London." 

 It was ascertained that milk, vitreous humour, and turnip infusion, so 

 prepared and protected by the carbolised cotton caps, kept free from 

 organisms and retained their natural appearance and taste for periods 

 extending over six weeks. 



A second generation of the organism, which for convenience I may 

 call Bacterium foetidmn, was obtained by placing a small piece of the 

 wet stocking in one of the test-glasses, charged with pure vitreous 

 humour. This and all the succeeding generations were cultivated at a 

 temperature which varied between 94° and 98° F. The successive 

 generations were obtained by inoculating pure vitreous humour, with 

 requisite precautions. 



In twenty-four hours the surface of the vitreous humour was always 

 found covered with a delicate scum, which in forty-eight hours was 

 compact and tolerably resistant. 



In the scum of one day's growth and in the fluid below it organisms 

 were found as cocci, single and in pairs, in transition stages towards 

 rod formation, as single and jointed rods, and as elongated single rods. 

 Many of the rods were actively motile. 



The compact scum of two days' growth was sufficiently resistant to 

 be removed in an unbroken sheet. When disturbed by the needle it 

 fell to the bottom of the glass. It was found to contain all the forms 

 found in the twenty-four hours' growth, and in addition long unbroken 

 rods in transition stages towards the formation of chains of spores. 



Spores were also found lying beside the empty and partially empty 

 sheaths from which they had been discharged. Groups of single 

 spores and pairs, identical in size and appearance with those which 

 had come to maturity in the sheaths, were found mixed up with rods 

 in all phases of development. 



As no individual coccus or rod was kept under continuous observa- 

 tion, the process of growth can only be inferred by comparing the 



