60 REPORT ON BOTANY, MDCCCXLI : 
phakocysts are subsequently discovered in the centre of the 
granular mass, each with a clear central point. The granular 
mass disappears after some time, without any of the phakocysts 
becoming enlarged. At last, in the middle of the month of 
August, four months after the commencement of the observa- 
tions, the vegetable cells exhibit themselves as consisting of 
concentrated layers, with a cavity in the middle, in which the 
four commencements of the pollen grains appear surrounded 
by a liquid. They gradually increase in size, and the thick 
pollen cell, consisting of layers, finally disappears altogether. 
The pollen cells in the Malvaceae, , at least in Hibiscus syriacus, 
have already a considerable thickness, before we can perceive 
the commencement of the pollen grains, because the matter 
witliin them is clear as water. It only afterwards, when it 
forms new products, becomes granular, for the first traces 
of phakocysts are subsequently discovered in the granular 
matter. The granular matter subsequently separates itself 
into four masses, which contain a phakocyst ; and a clear ring 
is seen round each of these four masses, which shows that they 
do not altogether fill up the pollen cell. The pollen cells have 
a covering, consisting of layers, like the starch granules, and 
they also shoot up in a similar manner, on placing them in a 
drop of water. The membrane of the pollen cells, according 
to the opinion of the author, is not produced from the internal 
surface of the pollen cells. The author adds, — “ The anthers 
of all flowers first attain their essential characteristics, when 
the other flowering organs are scarcely perceptible. On rolling 
young pollen grains between two glass plates, their external 
membrane is not removed, but the granules are torn, and their 
phakocyst escapes ; on the other hand, the external membrane 
of ripe pollen grains is easily separated, and the internal cell 
contains only granules, but no phakocysts.” 
IMPREGNATION — OVULE —SEED. 
We shall here proceed with the researches, which M. Decaisne 
has instituted, respecting development in the mistletoe. On 
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