34 



In the upper end of the young plant a cell-division now takes 

 place, resulting in a number of cells arranged more or less regu- 

 larly (Fig. 20 c). In this stage of development our plant has some 

 likeness with a small Valonia but when Schmitz also compares 

 it to a Cladophora I may point out, that I have never found any 

 specimen resembling that genus. How the cell-division takes 

 place in the quite young plant (see Fig. 20 c) I have not seen, but 



Fig. 20. Dictyosphceria favulosa (Ag.) Decsne. 

 (I, part of a thallus with cells in different stages of cell-division (6:1), 

 h, transverse section of thallus with cell newly divided (compare text) (20:1), 

 c, d, e, young plants (10 : 1;, /, chromatophores with pyrenoids and nuclei (250: 1). 



I have no hesitation in assuming that it is accomplished quite 

 in the same way as I have found it in older specimens, namely 

 by segregative cell-division. 



This is performed in the following way. In some of the cells 

 we find that the whole cell contents with chromatophores, nuclei 

 etc. have been aggregated into a number of spherical clumps 

 from two to six or even more, but most commonly three to 

 four (Figs. 20 a and 21 a). At first these spherical bodies fill up 

 far from the whole lumen of the mother cell but after becoming 

 surrounded with a membrane they begin to increase (Fig. 21b), 



