YEASTS 69 



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are located in the cytoplasmic web. The nucleus is situated on one 

 side of the cell, surrounded by a thin layer of very thick and homo- 

 geneous cytoplasm which is to become the sporoplasm, at whose 

 expense the ascospores are formed, the remainder— that is to say the 

 vacuolar cytoplasm— being destined to compose theepiplasm or nourish- 

 ing plasm. 



At a later stage, the metachromatic corpuscles undergo a kind of 

 pulverization transforming them into sniall grains, and begin to dis- 



FiG. 52. — Sporulation in Saccharomyces ludwigii. Figs, i and 7 showing the 

 evolution of the nucleus. Figs. 8-9, the metachromatic corpuscles, stained by a 

 method permitting a difEerentiation, except in Fig. 8, are dissolving, and the sub- 

 stance of the vacuole which contains them shows a diffuse metachromatic coloring 

 (here gray) like the corpuscles. 



solve in the vacuoles surrounding them, the latter at this time taking, 

 with aniline blue stains, a diffuse red coloring similar to that of the 

 metachromatic corpuscles (Fig. 52, 9). At the same time, the nucleus 

 undergoes two successive divisions, but these have not been discern- 

 ible up to the present time, because of the density and the strong 

 chromaticity of the sporoplasm surrounding the nucleus. They are 

 manifested merely by the appearance of the two daughter cells which 

 migrate to the two poles of the cell, carrying with them a part of the 

 sporoplasm, which assumes the appearance of a dumb-bell and whose 



