35 



growing closer together and at the same time becoming arranged 

 in the same plane as the other cells in the plant, which as already 

 described by Harvey consists of a single layer of cells only. When 

 the cells are grown quite together (Fig. 21 c) filling up the w^hole 

 lumen of the mother cell they assume its form, growing poly- 



Fig. 21. Dictyosphceria favulosa (Ag.: Decsne. 

 a, l, c, different stages of cell-division, in a the cell contents have been con- 

 tracted to balls, in i the young cells fill up nearly the lumen of the mother- 

 ceil, in c the young cells are quite developed, the walls of the mother cells 

 are seen over the young cells (10:1). d, wall of a cell torn loose from the 

 neighbour-cell showing arrangement of haptera (25:1). e, small part of d 

 more magnified; in the small cells chromatophores are seen; the oval rings 

 upon them are the bases of the hapteras, in one place the ends of the 

 hapters broken of from the neighbour-cell are seen ( 100 : 1 1. /, hapters between 

 two cells seen from above showing their alternating arrangement (1.5(i:l). 



gonal, and along their uppermost and lowermost edges appear 

 the small hapters which very regularly and alternately (Fig. 21 /) 

 fasten the neighbouring cells together. 



3* 



