183 NOTES AND MEMORANDA. 



different directions of space, the celluloselamellsejhowever, Still 

 sharply contoured. As in Ulothrix (previously described by the 

 author) Clylindrocapsa takes on too a " Hormospora-stage," 

 the cells in either a filament or in groups. The confervoid 

 habit indeed is maintained only so long as the cell-division 

 takes place transversely ; the joints are then cylindrical or 

 discoid, with flat or rounded end-surfaces. If, however, a 

 strong development of the outer laminae ensues, the plant 

 retains its filamentary form, but it appears as a chain-like 

 concatenation, consisting of green oval cells separated by the 

 intervening laminae. This is the form or state originally 

 figured by Reinsch, and similar to that in which it has twice 

 presented itself to ourselves. But as described by Cienkowski 

 median and oblique walls may occur ; such filaments present 

 numerous expansions or balls, lending to them a gnarled 

 aspect, the whole still surrounded by a common sheath ; but 

 lying for a time this disappears, and the cells break up into 

 formless aggregates of two, four, or more cells. 



The author had not seen zoospores,but supposes their occur- 

 rence doubtless, as he found examples on the side of the 

 glass vessel, which could only have originated from zoospores, 

 as the whole plant is destitute of any spontaneous motion. 



This alga possesses antheridia and oogonia. The oogonium 

 (b, c, d) is a globular inflated joint ; it consists of contents and 

 wall ; the first presents a protoplasmic gonosphere, coloured by 

 chlorophyll, containing numerous starch-granules ; it presents 

 at one point of the periphery very often a clear spot. The 

 gonosphere is loosely enclosed by the several (3-6) concentric 

 gelatinous (as it were swollen or expanded) membranes. 

 Such oogonia lie either several tog ether, forming a moniliform 

 chain (e), or they present themselves in the middle of a series 

 of antheridia, or between unaltered vegetative joints, upon 

 which, further on, may abut antheridia (c,d). Cylindrocapsa is 

 thusmonoicous. At both poles of the oogonium the coats are 

 produced into a short cylindrical process ; adjoining processes 

 are mutually apposed (b). The size of the oogonia varies; 

 it may reach 0-042 mill., the gonosphere 0024 mill. 



The antheridia are discoid or spheroidal little cells, like the 

 oogonia possessing a multilaminated coat (d, a) ; they may 

 form a long series or little groups of pairs ; they are often en- 

 veloped in twos or fours by numerous laminae (d, a). The con- 

 tents are clear reddish-yellow. The male-cells (like the vege- 

 tative) are formed by binary division of the mother-joint, with 

 the distinction that they cease to grow, remain smaller and 

 gradually assume the yellowish-red colour. Each antheri- 

 dium developes by division of its contents two spermatozoids. 



