The following are some of the numerous microscopic observations which we made on the liquids and their deposits. On June 1st the liquid in one of the six flasks which had begun to ferment was covered with a continuous scum of _mycoderma vini_, below which appeared a filamentous network belonging to a _mycelium_, or other fungoid growth. But neither in the liquid itself nor in the deposit could we perceive any cells of the ferment of beer; the field, however, was swarming with active butyric _vibrios_, rather thick and short, their length being about twice their diameter. This fermentation was exclusively butyric. On June 2nd another of the flasks showed no _vibrios_, but alcoholic ferment in small quantity, much lactic ferment, consisting of little particles contracted at the middle and non-mobile, and, finally, some slender filaments, resembling those represented in Plate I., Nos. 1 and 2. On June 3rd we examined the liquid in the flask which showed the most marked fermentation. In addition to the flakes of fungoid growths, checked in their development through want of air, we found at least five distinct productions, which are represented in the accompanying sketch (Fig. 11). _aaa._—Thick cells of alcoholic ferment, the size of which is given in our sketch: thus, 13/450 indicates that the corresponding figure is 13/450 millimetre in length (rather more than 1/1000 inch). _bbb._—Small alcoholic ferment, such as we generally see in the must of acid and sugared fruits—especially in filtered grape must. Its dimensions varied from 1 to 1-½, or 2, 450ths of a millimetre.[43] [Illustration: Fig. 11.] _ccc._—“Low” yeast, of a type resembling that existing in other preparations fermenting in the room. _ddd._—Enlarged, distended spores of _mucor racemosus_. These are scarce, and have an old appearance. We shall come to them again in a subsequent chapter, where we shall explain their real significance. _eee._—Short _vibrios_, occurring either contracted or not near the middle. Some were motionless, others vibrating to and fro and executing other movements. These forms belong to the butyric and lactic ferments shown on Plate I. The preceding series of experiments shows us that, in the case of wort exposed to the air, germs of divers organisms, amongst which various ferments—butyric, lactic, and alcoholic—are to be found, fall simultaneously from the particles of dust floating in the air. We must observe, however, that we were dealing with the air of a laboratory in which we were constantly studying analogous fermentations, and that a different atmosphere would, most likely, give us different results. We shall see a proof of this in the following paragraph, where we shall also find some new facts tending to prove that the germs of alcoholic ferment do not exist amongst the particles of dust floating in the air, in anything like the quantity usually supposed.