NOVEMBEK 27, 1896.] 



SGIENGE. 



775 



peptone used was then tested for indol, and 

 of five bottles tested each gave a distinct 

 indol reaction. Sargent's peptone was then 

 substituted for Witte's and uniform results 

 were obtained. 



All of the different varieties of this group 

 were found to be motile. Specimens were 

 stained in order to compare these types 

 with Stoeklin's groups of the colon bacillus, 

 which are differentiated by the number of 

 flagella. The writer was never able to at- 

 tribute a certain number of flagella to any 

 one variety, and each specimen showed a 

 much greater number than was found by 

 Stoeklin in the cultures forming his group. 



From a study of these types of the colon 

 bacillus group, it does not appear that any 

 one or two characteristics can be relied upon 

 to distinguish a variety ; for great variations 

 have been found in all of the important 

 functions of the specimens tested. One of 

 the most marked types is that described as 

 the pseudo-typhoid bacillus, which does not 

 ferment sugars nor produce indol, two of 

 the functions especially observed when de- 

 termining the typical colon bacillus. Such 

 widely varying characteristics seem to indi- 

 cate the necessity of using all of the biologi- 

 cal features for the differentiation of a mem- 

 ber of this group. 



The fermentation test as given by Smith 

 was used by the writer as the initial step 

 for distinguishing and classifying cultures 

 obtained from many different sources. The 

 greater proportion was taken from the de- 

 jections of patients or animals sick with in- 

 testinal diseases, and especially from ty- 

 phoid dejections obtained from a number of 

 patients. 



Gelatine plates were made from the ma- 

 terials investigated and a series of cultures 

 was taken from such colonies as seemed 

 characteristic of the colon bacillus. Each 

 series was carefully tested in regard to indol 

 production, fermentation, motility, etc. 

 The fermentation tests were made with dex- 



trose, lactose and saccharose, in one per 

 cent, solutions. Meat extract bouillon was 

 used with glucose, but for lactose and sac- 

 charose a special medium free from muscle- 

 sugar was required. An acid-albumin me- 

 dium was found to be free from sugar and 

 also from indol. This proteid solution was 

 tested by Pere,* using muscle for its produc- 

 tion, and was found to give a luxuriant 

 growth of the colon bacillus. Ohlmacher' 

 recommends peptone prepared from egg- 

 albumin. The writer has prepared it as 

 given in foot note.* 



Two hundred cultures were tested regard- 

 ing fermentation with the three varieties of 

 sugar. The cultures obtained from typhoid 

 dejections were found to give somewhat less 

 gas with lactose and saccharose than the 

 standard colon bacillus described by Smith, 

 which gave with glucose a volume of one- 

 half of the fermenting tube ; with lactose 

 the same amount ; with saccharose two- 

 thirds. No culture was obtained from 

 human dejections in which there was com- 

 plete absence of fermenting power for one 

 or more of the sugars. 



A series of cultures taken from the intes- 

 tine of a dog with ulcerated intestines was 

 quite typical in appearance and reaction. 



Cultures taken from the intestine of a 

 healthy rabbit gave only a small amount of 

 gas with glucose, and none with saccharose. 

 FremHn found that the colon bacillus from 

 rabbits varies from that found in man ; but 

 his fermentation tests were decided by glu- 

 cose alone. 



The fermentation test was also applied to 

 cultures of the colon bacillus obtained from 

 specimens attenuated by growth under very 



* The whites of two eggs are well-beaten and mixed 

 with 500 c. cm. of distilled water acidified with 2 o. 

 cm. of concentrated hydrochloric acid. Two and a-half 

 grammes of scale pepsin are used for the digestion of 

 this mixture, which is kept at a temperature of 40° C. 

 for six hours. It is then neutralized, one-half per 

 cent, each of peptone and salt are added, and enough 

 water to make one litre, when it is boiled and filtered. 



