. NOTE ON A PINK TORULA. 269 



sent in the culture numerous cells of the yeast Saccharomyces 

 cerevisiae. The cells are oval, consisting of a limiting mem- 

 brane and a homogeneous, highly refractive protoplasm, and in 

 it at one place one or two vacuoles. In some of them there 

 was one large bright corpuscle present at one side of the pro- 

 toplasm. In some the protoplasm appears slightly granular. 

 The cells are of different sizes, some twice as big as others. 

 Their sizes are as follows : the big cells 0*009 mm. by O'Ol mm., 

 the small ones 0*005 ram. by 0*008 mm. The small ones are 

 evidently young forms, since they could be seen to sprout out, 

 and to become constricted off from bigger ones. 



As regards the process of reproduction, it appeared to me to 

 be that of gemmation only. Hereby large groups of cells, 

 some chain-like, were formed, which groups by enlargement 

 become soon confluent into larger masses. 



The pork broth, kept at 32° C, for several weeks, became so 

 concentrated, that when taken out of the incubator and allowed 

 to cool, almost solidified. Keeping it in this state at the 

 ordinary temperature of the room, it was noticed, after some 

 days, that the growth appeared on the surface of the nourish- 

 ing material in the shape of minute whitish spots or flat 

 droplets, which, as they gradually enlarged, assumed a distinct 

 pinkish colour. The enlargement in breadth and thickness 

 proceeded in a few days so far that the whole surface of the 

 almost solid nourishing material became covered with a 

 pinkish film, in which, however, the individuality of the drop- 

 lets could still be recognised. Under the microscope these 

 pink droplets are composed entirely of torula cells of exactly 

 the same nature and size as those above described. They are, 

 no doubt, the same organisms, as will appear also from other 

 facts presently to be mentioned. 



The cells themselves do not possess any colour when looked 

 at under the microscope, singly or in a thin layer, but they 

 appear of a pinkish tint when viewed as a group, or in a thick 

 layer. 



I have sown out from this* layer of pink torula cells on to 

 boiled white of egg, solid gelatine, and mixture of gelatine and 



