STUDIES ON FERMENTATION. 155 



different forms were all produced in the course of twenty- four 

 hours by the cell which may be observed in the centre of the 

 group J. In connection with this same group, J, we may 

 remark that on September 30, 1872, at 10 a.m., we witnessed 

 the detachment of three oval cells at the points a, h, c ; by 10.45 

 other buds of the size represented in our engraving had formed 

 in their place ; b}' about five o'clock that same afternoon these 

 buds, a, b, c, having become transformed into cells, fell off in 

 their turn.* 



* For these observations, we employed small glass cells, whicli we 

 made out of some St. Gobain glass by punching holes through it, and 

 then cementing on one side one of the little glasses used for covering 

 objects in microscopical examinations. In this manner we made small 

 troughs, in which we placed some wort that had been boiled, and a drop 

 of the water in which grapes had been washed. To prevent evaporation 

 we covered the cells with a sheet of glass. We examined the liquid in 

 these cells by inclining our microscope to the angle required, (a) 



Fig. 29. 



We also made use of cells similar to those employed by MM. Van 

 Tieghem and Lemonnier {h) in their researches on mucorines (Fig. 30). 



B aIK TF " B 



Fig. 30. 



An apparatus similar to that employed by M. Duclaux in 1853 (c) would 

 do equally well. We should be able to work with even greater facility 

 if we employed bulbs like some which we ordered in Germany, some 

 twelve years ago, of the well-known glass-blower, Geissler. We have 

 heard that these bulbs now sold by that maker are much used by 

 German microscopists. They consist of a tube blown out into a flat 



(a) In our essay on acetic fermentation, published in 1864, -we have already described this 

 apparatus, -which we employed to foUow the multiplication of the jointed filaments of myco- 

 derma aceti. See Pasteur, Etudes sur le vinaigre, p. 64, Paris, 1868. 



(ft) Van Tieghem and Lemonnier, Annales des Sciences naturelles, 5th series, Botanique, 

 t. xvii. 1873. 



(c) Duclaux, Comptts rendus des stances de I'Academie des Sciencts, t. Ivi. p. 122i. 



