yeast-plant: sarcina ventricult. 



353 



and return to the isolated condition of those which originally con- 

 stituted the yeast. Thus it is that the quantity of Yeast first 

 introduced into the fermentible fluid is multiplied six times or 

 more during the changes in which it takes part. The full develop- 

 ment of the Plant, and the evolution of its apparatus of Fructifi- 

 cation, however, only occur when the fermenting process is allowed 

 to go on without check; and it seems capable of producing a con- 

 siderable variety of forms, whose precise relationship to each other 

 has not yet been made clear. — The recent researches of M. Pasteur 

 have fully confirmed the belief previously entertained by many 

 Physiologists (though generally discountenanced by Chemists), that 

 all Fermentative processes essentially depend upon the develop- 

 ment of Fungous Vegetation in the substance undergoing change. 

 Thus he found that if Milk be boiled in a flask the mouth of which 

 is plugged with cotton-wool before the boiling has ceased, the milk 

 remains sweet for any length of time ; whilst milk boiled in a 

 similar 'flask left unstopped, first turns sour and then becomes 

 putrescent in the course of a few days. Air can enter with the 

 same freedom in the first case as in the second ; but in the first it 

 is filtered of the organic germs it carries. 



264. Many of the simpler forms of Fungi are inhabitants of the 

 interior of the bodies of other animals, and are only known as 

 living in these situations. Among these may first be mentioned 

 the Sarcina ventriculi (Fig. 166), which is most frequently found 

 in the matters vomited by persons suffering under disorder of the 

 Stomach, but has 



also been met with FlG - 166 ' 



in other diseased 

 parts of the body. 

 The Plant has been 

 detected in the con- 

 tents of the Sto- 

 mach, however, un- 

 der circumstances 

 which seem to in- 

 dicate that it is not 

 an uncommon ten- 

 ant of that organ 

 even in health, and 

 that it may accumu- 

 late there to a con- 

 siderable amount 

 without producing 

 any inconvenience ; 

 it seems probable, 

 therefore, that its presence in disease is rather to be considered as 

 favoured by the changed state of the fluids which the disease induces 

 (either an acid or a fermentible state of the contents of the stomach 



A A 



Sarcina ventriculi. 



