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POPULAR SCIENCE REVIEW. 
presumed sexuality, tlie u oogonia 99 representing the female, 
and the u antheridia 33 the male organs. 
The oogonia are large sphaerical or ovoid cells, with a 
thickish membrane containing a granular protoplasm, or 
formative fluid. They are produced either terminally or late- 
rally upon the threads of the mycelium, from which they are 
separated by septa or partitions. 
The antheridia are somewhat club-shaped or obovate cellules, 
considerably smaller than the oogonia, with slightly thickened 
walls and containing a finely granular protoplasm. These are 
produced upon branches of the mycelium which do not bear 
oogonia. The obtuse extremities of these branches, which are 
to be developed as antheridia, are applied to the surface of the 
growing oogonia, to which they adhere, become distended, 
assume their obovate form, and by the formation of a septum 
at their base, their contents are isolated from those of the 
threads of the mycelium, and thus the antheridia are perfected. 
When these bodies have attained their full dimensions, the 
large granules which are contained in the oogonium accumu- 
late at its centre, and form an irregular, somewhat spherical 
mass, which is called by De Bary a gonosphere. This gono- 
sphere having been formed, a straight tube shoots out from 
the antheridium which perforates the wall of the oogonium, 
passes through the fluid which surrounds the gonosphere, 
elongating itself until it touches that body. From this period 
a membrane begins to be formed about the gonosphere, which 
thenceforth maintains a regular spheroidal form. It may be 
observed that the extremity of the tube which proceeds from 
the antheridium does not open, and the fecundation, if such it 
be, is produced solely by contact. After this contact of the 
two bodies the gonosphere acquires a new name, and is called 
an “ oospore.” The membrane which at first invests this 
organ is very thin, but by deposits from the surrounding fluid 
it attains to a greater thickness, and is at length of a yellowish 
brown colour, having its surface studded with large, obtuse 
warts. One of these warts, larger than the rest, forms a kind 
of thick sheath around the fecundating tube. 
The oospores do not give evidence of any appreciable change 
for some months. For instance those collected by De Bary 
in June did not attain their ulterior development until the 
commencement of December. The method adopted was as 
follows : — Parts of the plants containing ripe oospores were 
preserved in the dried state. When examination was consi- 
dered desirable, the portion to be employed was immersed in 
water for a day or two ; it was then placed on a humid soil, 
or mould, covered with blotting-paper. The tissues enclosing 
the oospores were decomposed, and at the end of from four 
