CONFERVACEE, 187 
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 » 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 is 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 bombycina var. genuina has similar 
resting-spores. 
Three modes of formation of resting-spores of Confervaceew 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. Berk. Glean. t. 14, f. 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. 
Siz. Threads ‘016-018 mm. diam. 
Kutz. Tab. iii., t. 45, £4. Rabh. Alg. Eur. 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 LILI. jig. 6. Threads of C. fontinalis X 150. Fig. 7, por- 
tions of threads X 400. 
Conferva tenerrima. Kutz. Tab. II1., t. 42, f. 1. 
Usually pale green, articulations 14-8 times as long as the 
diameter. 
Sizz. Threads °0035--004 mm. diam. (:003--005 mm. 
Kirschner). 
Rabh. Alg. Eur, iii., 8322. Kirsch. Alg. Schl. p. 78. 
In fresh water, often mixed with other Alga. 
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. 
