Ethel M. Doidge 69 



become very densely clouded ; a slightly heavier growth was observed 

 in peptone water to which potassium nitrate had been added. 



Nutrient houillon over chloroform; growth was unrestrained in the 

 presence of chloroform; the tubes were clouded in 24 hours, turbid in 

 48 hours. 



Litmus mill' is slowly peptonised. After 24 hours at 25° C, the 

 fluid is clear to a depth of about 2 mm. from the surface, the remainder 

 of the milk being unchanged. After 5 — 6 days the upper third of the 

 medium is clear and translucent, the middle third is partially pep- 

 tonised, and the remainder still opaque and unchanged ; the medium 

 thus exhibits three strata of approximately equal depth. In 8 — 10 

 days the whole of the milk has been peptonised, the colour is at first 

 unchanged by reflected light and reddish by transmitted light, but it 

 finally becomes slowly reduced from the top downwards leaving a 

 yellowish translucent fluid. There is a small amount of sediment. 



Egg albumen. A medium composed of 1 grm. powdered egg albumen 

 in 50 c.c. of -05 % potassium phosphate was used to determine the 

 proteolytic activity of the organism. The medium after sterilisation 

 is a colourless li([uid in Avhich the insoluble part of the egg albumen 

 has been separated out in white flakes ; when planted with the organism 

 the liquid became clouded and then became deep sea foam green in 

 colour. The solid albumen was acted upon and became slimy and soft 

 in consistency. 



UschinsJij/'s solution is clouded in 24 hours at 25° C, after six days 

 it is very turbid, first the upper part of the broth, and gradually the 

 whole of it becoming light, dull, green yellow to clear, dull, green 

 yellow, the colour being much more noticeable by reflected than by 

 transmitted light. There is a fair amount of sediment and the rods 

 are normal and active. There is a ring above the medium, and a pelhcle 

 which sinks if the tube is shaken. 



At the end of 20 days the pellicle still continues to form, and to 

 sink when disturbed. A very heavy deposit is thus formed which 

 is very viscid and almost like egg albumen in consistency. After 

 some weeks the liquid becomes clear but yellowish ; there is some 

 yellowish growth clinging to the sides of the tube and a deposit 1 — 2 cm. 

 deep in the bottom. 



The organism also grows, but less vigorously, in a solution from 

 which the asparagin and ammonium lactate have been omitted and 

 replaced by ammonium sulphate. The organism is therefore able to 

 obtain its nitrogen from a simple salt. 



