244 



Chlorophycece 



Genus Apiocystis Nag., 1849. The gelatinous colonies are 

 relatively small and attenuated towards the base, which is usually 

 fixed to other larger Algae. The cells are similar in structure to 

 those of Palmella, and they are disposed without order near the 

 periphery of the gelatinous vesicle. Each cell is furnished with 



two ' pseudocilia,' which 

 penetrate through the 

 jelly into the surround- 

 ing water. Multiplication 

 occurs by the division of 

 the cells in two or three 

 directions accompanied 

 by a corresponding in- 

 crease in the size of the 

 colony. Correns 1 states 

 that when a cell divides 

 one pseudocilium goes 

 to each daughter-cell, a 

 second one being subse- 

 quently developed. Re- 

 production takes place 

 by biciliated zoogonidia 

 and isogamous gametes 2 . 



Fig. 112. Apiocystis Brauniana Nag., from 

 near Bowness, Westmoreland ( x 400). 



A. Brauniana Nag. is not 

 uncommon in ponds, ditches, 

 bog-pools, etc., and its pyri- 

 form colony is commonly 



attached by the base to larger filamentous Algse. The colonies are 12 1000 p. 



(or upwards) in length and the cells 6 8 p. in diameter; fig. 112. 



Sub-family III. GLCEOCFSTIDE^. 



The colonies of this sub-family consist of an aggregate of cells 

 within a common mucilaginous envelope, which exhibits a lamellose 

 structure. As a rule concentric coats of mucus can be distinguished 

 round each individual cell or round a small group of daughter- 

 cells. The lamellation of the mucous integument reaches a 



1 Vide Bot. Centralbl. liv, 1893, p. 146. 



2 Moore in Journ. Linn. Soc. Bot. xxv, 1890. 



