4H 
Notes. 
time. I occasionally observed zoospores which still exhibited 
a jerking movement, whose one end had already commenced to 
form the tip. 
Cohn 1 2 gives figures of the development of a zoospore of Oed . 
capillar e, but gives no description thereof. The figures are excellent, 
but do not illustrate the details of the development. 
Developing zoospores of Oed. capillare are also figured by Kiitzing a . 
In Fig. 4 the germinating zoospore is shown, and this shows a well- 
developed root before the tip is scarcely developed. My observations 
in general do not agree with this, although occasionally the develop- 
ment of the tip commenced after that of the root. It is noteworthy 
that all the young plants figured by Kiitzing have long rhizoids, 
although some of them consist of as many as five cells. The fact 
that no disc is figured makes me rather doubtful whether he had the 
same species as I had 3 . 
Cleve 4 * only observed the germination of the zoospores derived from 
the sexual generation. Although much smaller, their appearance is 
very much like that of the common zoospores. The young plants 
possess a tip, and figures illustrating its development to some extent 
are added, but no details are given in the text. 
In my cultures the young plants rarely divided to form a several- 
celled filament, but after some two or three days again liberated their 
contents as a zoospore ; the upper part of the cell-wall together with 
the tip being pushed on one side like a hinged lid (Fig. 23, e). This 
is differentiated in the same way as in the cells of the adult plant, the 
contents rounding themselves off at the corners, and a distinct colour- 
less area being developed on one side. Indications of the formation 
of the lid are to be found some little time before the liberation of the 
zoospore. A little way below the tip the membrane shows a very 
slight thickening on its inner side, extending right round the circum- 
ference of the wall of the young plant, and appearing as a faint line in 
surface-view, and as two little knobs on the inside of the wall in optical 
section. This is the line along which the lid is split off. 
1 Untersuchungen iiber die Entwickelung der mikroskop. Algen u. Pilze. Leop.- 
Akad., 1854, vol. xxiv, pars I, p. 231. 
2 Phycologia generalis, 1843, p. 254, Tab. 12 11 , Fig. 4-10. 
3 The young plants of Oed. capillare usually possess a well-marked basal disc ; 
an elongated rhizoid is rare in this species. 
1 Ofvers. af K. Vet.-Akad. Forh., 1863, pp. 248, 249. 
