It has already been observed in our Memoir on spontaneous generation, that alcoholic fermentation is not always to be obtained by sowing wads of cotton or asbestos, charged with the particles of dust which float through the air, in saccharine musts that are in contact with much air. The air which furnished the particles of dust, in the experiments to which we are alluding, was taken outside the laboratory, in a neighbouring street. Footnote 42: The decanting into the flasks is necessary, because of the possibility of the fermentation in the basins being masked. See further on the note on p. 75. Footnote 43: This small ferment is very curious, although it scarcely affects industrial fermentation. It was first described in 1862. (PASTEUR, _Bulletin de la Société chimique_, 1862, page 67, and following: _Quelques faits nouveaux au sujet des levûres alcooliques_.) It has since been described by Dr. Rees under the name _Saccharomyces apiculatus_. (Dr. Rees, Leipzig, 1870: _Sur les champignons de fermentation alcooliques_. See also Dr. Engel, _Thèse pour le Doctorat_, Paris, 1872.) If we carefully filter some grape must at the time of vintage, we may be sure that we shall see it appear in the clear liquid at the bottom of our vessel, without intermixture with any other ferment. Should we not filter the must this ferment will appear all the same, but it will soon become associated with another, thicker in appearance and more elongated, which also is one of the ferments peculiar to the fermentation of grape must. Footnote 44: We may remind the reader that in 1862, in our _Mémoire sur les Générations dites spontanées_, we applied the expression of _torula_ to all the little cellular plants of spontaneous growth, excepting _mycelium_, propagated by budding, after the manner of the ferment of beer. At the same time, stress was laid upon the frequent occurrence of their germs, especially in our laboratory, where studies on fermentation were, even then, carried on. Plate III. represents two of these ferments. Footnote 45: