COKFERVACE.E. 137 



other, and covering it like the lid of a box. Afterwards, through the 

 expansion of the inner membrane, the smaller piece of the outer mem- 

 brane gives way, and the inner membrane grows through the aperture 

 thus formed in the form of a tube. The development was not followed 

 further, but the writer considers it probable that zoospores are first 

 formed from the resting spores." 



In Conferva bombycina, var. minor, either single cells swell up into a 

 barrel shape, or here and there the contiguous ends of two neighbouring 

 cells assume a club-like form. It is here that the largest part of the 

 Chlorophyllaceous protoplasm accumulates, and after this the swollen 

 end iB separated by a transverse wall from the longer narrow part of the 

 mother-cell. The wall of the swollen part thickens later. The author 

 considers these cells to be resting-spores, although he was not able to 

 observe their germination. Conferva, bombycinavax. genuinahas similar 

 resting-spores. 



Three modes of formation of resting. spores of Oonfervacece have been 

 observed (1) by rejuvenescence, and the formation of a new membrane 

 round the contracting contents ; (2) by the thickening of the membrane 

 of the mother-cell ; (3) by separation of a portion of the cell substance 

 to a swollen part of the mother-cell, and the thickening of the membrane 

 of this portion. 



Conferva fontinalis. BerTt. Glean, t. 14, /. 1.. 



Bright green, attached ; articulations 6 to 10 times as long 

 as the diameter, slightly swollen, a little constricted at the 

 joints, starch granules single, scattered or seriate, cell-membrane 

 rather thick, homogeneous, when heated with sulphuric acid 

 swelling and distinctly lamellose. 



SIZE. Threads -OIG-'OIS mm. diam. 



Kutz. Tab. iii., t. 45, f. 4. Eabh. Alg. Ear. iii., 323. Kirsch. 

 Alg. Schl. p. 78. 



Attached to grass, &c., in ditches. 



" It covers rushes, grass, &c., with a short downy green coat, which is 

 very conspicuous in spring and summer." Berkeley. 



Plate LI11. jig. 6. Threads of C. fontinalis X 150. Fig. 7, por- 

 tions of threads X 400. 



Conferva tenerrima. Kntz. Tab. in., t. 42, /. 1. 



Usually pale green, articulations 1J-3 times as long as the 

 diameter. 



SIZE. Threads '0035--004 mm. diam. (-003--005 mm. 

 Kirschner). 



Rabh. Alg. Eur. iii., 322. Kirsch. Alg. Schl. p. 78. 



In fresh water, often mixed with other Algaa. 

 Plate LIII., fig, 5. Portions of threads of C. tenerrima X 400. 



Conferva bombycina. Ag. Syst.p. 83. 



Yellowish green or green, soft, silky ; articulations oblong- 

 cylindrical, slightly constricted at the joints, before division 

 three times as long as the diameter, collapsing alternately when 

 dry. 



