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On some Britisu FresH-waTter ALG. 
By Freperick Currey, Hsq., M.A., F.R.S. 
Tue observations to which this paper relates were made in 
the year 1856, and have since been laid by under a doubt 
as to their being of sufficient importance to be made public ; 
but some recent observations inGermany have induced me to 
think that they may not be without value, especially if they 
should have the effect of directing the attention of some of 
the numerous microscopists of the present day to the abund- 
ance of material for interesting and important microscopical 
inquiries afforded by the fresh-water Alge. 
The first matter to which I wish to direct attention is a pecu- 
har condition of fructification of the common Draparnaldia 
glomerata. When this plant is taken from the water, it pre- 
sents, as 1s well known, a shiny gelatinous mass of a uniform 
yellowish green colour, and without the aid of the microscope it 
is impossible to trace its structure. In the month of April, 
1856, I found, in a pool of water in a gravel-pit in Cobham Park, 
a quantity of Draparnaldia glomerata, in which the jelly 
was traversed by multitudes of dark-coloured feathery-look- 
ing lines, clearly visible to the naked eye, and upon examin- 
ing it with the microscope, it appeared that almost all the 
side shoots of- the Alga had become transformed into rows of 
globular brown cells, arranged in a moniliform manner. 
These cells were, in most instances, in close contact with 
one another, but here and there single cells were to be seen, 
which, although isolated, clearly belonged to the same con- 
geries. It was obvious that these brown cells had been 
originally formed in the interior of the joints of the side 
shoots of the Alga, and were, at the time of the observation, 
gradually becoming free by the dissolution of the walls of 
the parent cells, the debris of which helped to form the ge- 
latinous medium in which they were immersed. Fig. 1 
represents the general appearance of a portion of the plant 
under a power of 200 diameters. It will be seen that at one 
point, at the extremity of one of the shoots, the formation 
of the brown cells is not complete, the three terminal cells, 
retaining still their primary oblong form and their original 
pale green colour. I am not aware that this state of fructi- 
fication in Draparnaldia has ever been described. The or- 
dinary mode of reproduction of this Alga is by zoospores, 
which are emitted from the cells of the ramuli, and which 
are of a sub-globose or elliptical shape, and furnished with 
