Mr. W. K. Sullivan on the nature of Lactic Fermentation. 211 



instance of this may be mentioned the fact that the yeast plant 

 is continually taken into the stomachy and yet fermentation does 

 not ensue, except where the stomach is diseased, and then the 

 yeast plant grows rapidly, as has been discovered by an examina- 

 tion of the matter rejected from the stomach. The yeast plant 

 has even been found under those circumstances where the patient 

 has not partaken of fermented drinks. The fungus found in 

 urine during acid fermentation, and which so closely resembles 

 the yeast plant, has always been observed after the urine has 

 been some time voided. There is no proof whatever that it ever 

 germinated within the bladder during life. On the other hand, 

 parasitic fungi are often found on putrid ulcers, but only on 

 the uninjured skin or mucous membrane when it has become 

 previously covered with a layer of exudated matter which has 

 begun to pass into a state of decomposition. The growth of 

 fungi, once established, may no doubt spread to healthy parts, as 

 in certain skin diseases, and in bread mould, but it could never 

 commence upon a pei'fectly healthy clean spot. 



I have lately had occasion to observe how completely the 

 germination of the spores of fungi depend upon the existence of 

 certain conditions. I laid aside some small beaker glasses 

 covered tightly with filtering paper, and containing very strong 

 solutions of salts, consisting of sulphates of potash and of 

 chrome. The solution in one of the glasses had been treated 

 with excess of ammonia, and boiled for some time, and then 

 filtered to separate the small portion of the sesquioxide of 

 chrome which had been precipitated. After a few weeks, the 

 solution to which the ammonia had been added became filled 

 with an extremely beautiful rose-pink-coloured mycelium of a 

 Penicillium. Nothing grew in the others ; but on adding some 

 ammonia, the same mycelium was developed after some time. 



The supposition that the primum movens of fermentation is 

 the growth of specific ferments, appears to me to be so far 

 premature, that while there may be no doubt that the vegetable 

 form developed during alcoholic fermentation could not produce 

 the lactic, and vice versa, it has not yet been established that 

 they are specifically distinct. May not the same plant be forced 

 into difi"erent habits of development in its myceloid state ? If 

 the myceliuui produced in each kind of fermentation or putre- 

 factive change belonged to a peculiar species, it would be, to a 

 certain extent, an argument in favour of the view that fermenta- 

 tion is due to a vegetative process. But if, on the other hand, 

 the same species may be forced into two different myceloid states, 

 the estaljlishmcnt of the fact would go far to prove tiiat the 

 chemical change is the cause and not the result of the vegetative 

 process. 



P2 



