THE BIOLOGY OF MICROBES, ETC. 137 



Bacterium lactis. The cells measure from T5 to 

 3 IJL in length, and are constricted in the centre like 

 the figure 8. They occur singly, in long chains, 

 zoogloea, and like B. aceti, they are motile. Bac- 

 terium lactis is the cause of the lactic fermentation 

 or the souring of milk. The sugar of milk or lactose 

 is converted into lactic acid by the growth of this 

 microbe (Lister *). Unlike B. aceti, this microbe is 

 anaerobic. B. lactis, along with other microbes, 

 plays an important part in the preparation of sauer- 

 kraut ; and Dr. Baginski has recently shown that it 

 produces a powerful reducing action in pure cultiva- 

 tions, where the nutrient fluid was coloured with 

 methylene blue. 



Bacterium decalvaiis. This microbe was discovered 

 by Dr. G. Thin 2 in the roots of the hair in cases of 

 Alopecia areata ; and he supposes that it penetrates 

 downwards between the root-sheath and the hair, 

 then passes through the cuticle of the hair, and 

 ultimately ascends within its substance, causing it 

 soon to fall off. It measures 1*6 /*, in length, and 

 occurs usually in pairs. 



Bacterium cholercegallinarum. This is the microbe 

 of fowl cholera, and it is found in large numbers in 

 the blood and organs of fowls dead of this disease. 

 It measures 1*2 to 1-5/4 in length, and the ends are 

 always stained more deeply than the middle part. 

 B. cholerce gallinarum is easily cultivated in chicken 

 broth (neutral) at 25 35 C., and when fowls are 

 inoculated with a drop of this culture they always 



i Transactions of the Pathological Society, 1878. 

 Proceedings of Royal Society, vol. xxxiii. p. 247. 



