CELL DIVISION 



11 



Fig. 7. Budding 

 in Saccharomycodes 

 Ludwigii. 



True transverse partition is met only with the Schizosaccharomyces 

 of which we shall mention the principal species. 



Sch. octosporus possesses round or oval cells; in young cells the 

 oval form predominates. They elongate and, after having acquired 

 a certain size, form a wall across the middle. This 

 splits apart and the two cells become rounded. 

 They elongate when they have achieved their 

 growth, and finally separate completely; but often 

 the two cells, though remaining attached, undergo 

 a new partition which makes two daughter cells. 

 Thus a row of cells is secured which are arranged 

 parallel to each other. Sometimes, when multi- 

 plication is very rapid, a primary transverse wall is formed which 

 makes two cells; without separating, these produce 

 another partition. In this manner, small filaments 

 may be found which eventually break apart. 



At the end of some culture periods and also 

 under certain conditions the cells show a tendency 

 to take spherical forms. In this case partition is 

 accomplished in the same manner; but it also often 

 happens that, on account of rapid multiplication, 

 the two cells set apart by a partition remain at- 

 tached without rounding their adjacent planes. 

 Each may then form transverse partitions which 

 form two new cells, 

 (according Such an arrange- 

 ment resembles the 

 sarcina grouping. In this latter case par- 

 tition is accomplished in two directions. 

 The daughter cells remain associ- 

 ated for some time, giving the appear- 

 ance of colonies. These colonies 

 present different appearances, depend- 

 ing upon the age of the culture. In 

 the early stages of their development 

 these colonies are composed of elongated 

 cells. Later muriform cells are apparent. Fig. 9. Partition 



In the other Schizosaccharomyces 

 (Sch. Pombe and Sch. mellacei), in which 

 the cells look like drum sticks, division is accomplished in the same 

 manner. When they have acquired their maximum size, the cells 

 form a partition, which divides them into two cells. They either 

 separate immediately or remain attached for some time. 



Fig. 8. Showing 

 Partition in Schizo- 

 saccharomyces octo- 

 sporus 

 to Schionning). 



Pombe 



in Schizosac- 

 (according to 



