Page:The yeasts (1920).djvu/36

 In the latter case, they are able to turn about and, remaining attached, undergo a transverse division as with Sch. octosporus. They often remain completely adherent to form a chain with 2, 3, or 4 elements. Under certain conditions, notably in an environment with too little air, the cells show a very marked tendency of adhering together in chains which branch.

Sulc has proven the existence in certain Schizosaccharomyces of certain fatty bodies. These Schizosaccharomyces multiply differently by partition or budding. This should be confirmed.

Durable Cells

In the pellicle which appears after a period of time on the surface of nutrient media, and in deposits at the bottom of flasks containing certain special media (sugar solutions containing tartaric acid or citric acid and mineral matter), Will has observed cells which possess thick walls and whose contents are rich in glycogen and fats.

From the researches of Will and Casagrandi, these cells possess a double membrane; the outer one is very fragile and easily broken to pieces. These membranes are made more visible by treating the cell with osmic acid or by the Ripart-Petit fluid (hydrochloric and chromic acids, 1 per cent).

Will has called these cells