ON THE NATURE OF FERMENTATION. ISf 



the Bacterium lactis or tlie O'ldium lactis, but some other kinds 

 of fungi. That very simple experiment is enough to show that 

 the lactic acid fermentation is not a change to which unboiled 

 milk is spontaneously prone. And it occurred to me that^ if all 

 organisms and fermentations which occur in milk really depended 

 on accidental introduction from without^ by performing the ex- 

 periment with a number of purified glasses and taking the milk in 

 small quantities into each, we might by thus subdividing elude the 

 foreign element and get the milk, in some of the glasses at least, 

 not only without the lactic acid fermentation or the Bacterium 

 lactis, but without any fermentation or any bacterium, or any 

 sort of organism. Accordingly, I prepared little glasses like 

 these ; little test-tubes with test-tube caps, arranged upon a stand 

 made of pieces of glass-tube and silver wire. The stand con- 

 taining the test-tubes was placed under a glass shade on a plate 

 of glass and purified by exposure to 300 deg. Fahr. in the hot box. 

 Then some milk having been received from the cow into a purified 

 vessel by means of a a syringe attached to this pipette, the pipette 

 having been also purified, milk was drawn up into the pipette, 

 and then, by means of the syringe, each little cap being in suc- 

 cession raised, a few minims of milk were introduced into each 

 of the glasses, the caps being immediately reapplied. The result 

 was, every one of the milks underwent fermentation, and every 

 one of them contained organisms, some of them as many as 

 three different species. The great majority of those twelve glasses 

 presented little orange specks, such as were never seen, I suppose, 

 in any milk before ; and, on examining these, I found them to be 

 little organisms belonging to a group to which I have ventured 

 to give the name Granuligera, because they consist of granules, 

 different from bacteria in this respect, that you might suppose 

 them not to be organisms at all till you had the opportunity of 

 seeing them undergoing multiplication by fissiparous develop- 

 ment, in a manner, however, differing from the transverse fissi- 

 parous multiplication of bacteria, in being crucial. ^ But, besides 

 the Granuligera, there were among the contents of these test- 

 tubes bacteria of different kinds, to judge by form and size, 

 and in one of them was a toruloid organism, and in two others 

 two species of filamentous fungi, one of which was of the most 

 exquisite delicacy, though in general type of the same sort of ar- 

 rangement as the common blue mould or the Oidium lactis. The 

 size of the filaments was so exceedingly small that twenty of them 

 would lie abreast in a single human red corpuscle -, they were 

 smaller in diameter than even the Bacterium lactis, smaller than 

 the great majority of bacteria. I doubt if any such exquisitely 

 delicate filamentous fungus has ever been seen before even by a 

 * Vide ' Trans, of the Royal Society of Edinburgli,' vol. xxviii, p. 319. 



