CELL DIVISION 



9 



saccharomyces priorianus and japonicus and S. Ludwigii. In this last 

 variety, Hansen has proved the production of a well-developed my- 

 celium; however, this mycelium is rarely composed of elements which 

 are solidly united. The cells are, however, separated by well-marked 

 walls, and each is able to thrust 

 out buds or to develop ascospores. 

 Certain parts of the mycelium offer 

 very abnormal forms. 



With certain species, the growth 

 which is formed at the bottom of 

 a flask during fermentation has a 

 tendency to produce filamentous 

 formations. Thus with S. marxianus 

 has been observed the formation 

 of little flakes of mycelium which 

 rest on the bottom of the flask or 

 float lightly in the liquid. Recently 

 Lepeschkin 1 secured with Sch. 

 Pombe and mellacei, under certain 

 conditions, the formation of little Fig 5 _ Mycelial Formations in Old 

 flocks presenting all of the charac- Scums of Saccharomyces Ludwigii 



. .. f v (according to Hansen). 



tenstics of a mycelium. 



Mycelial formations are found well developed in a yeast described 

 by Guilliermond in 1917 under the name of yeast from Pulque No. 

 2. 2 A typical mycelium was formed of budding yeasts in most media, 

 especially in the sediment which formed in beer wort as well as in the 

 flocculent particles which float in the medium, on slices of carrot, and 

 beer wort agar. The ascs seem to appear indifferently from the yeasts 

 and from units in the mycelium. 



CELL DIVISION 



(A) Budding 



Practically all of the yeasts divide by budding; it is the charac- 

 teristic method for multiplication. The bud appears as a little 

 prominence separated from the wall of the mother cell by a very 

 narrow collar. Little by little it increases in size. When it has 

 acquired a certain size, always smaller than the mother cell, it sepa- 



1 Lepeschkin, W. 1903. Zur Kenntnis der Erheblichkeit bei der einzelligen 

 Organismen. Cent. Bakt. Abt. II, 10. 



2 Guilliermond, A. Levaduras del Pulque. Boletin de la Direccion de Estudios 

 Biologicos. Mexico, ii, 1917. 



