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short. In the final division in the antheridium a reduction in nnmber 
occnrs, so that each antherozoid receives three chromosomes — one long, 
one of medium length and one short. 
According to the same authors (1908), each antheridial cell of Mnium 
has eight chromosomes — four long and four short. Each resting nucleus 
contains, besides a “chromatin clump”, a small granule which migrates 
into the cytoplasm and behaves like a centrosome, as in Polytrichum. Then 
the chromatin clump divides into two bodies, one of which passes into 
the cytoplasm and disappears. In the final antheridial division, the number 
of chromosomes is redueed to four — two long and two short. 
Wilson (1910, 1911) finds six chromosomes, of approximately equal 
length, in the antheridial divisions of Mnium liornum. The final division 
is not diagonal, and does not reduce the ehromosome number. In the 
propliases of the penultimate division, a body is formed by budding from 
the nuc-leole; preparatory to the final division, two bodies are similarly 
formed, one of which in turn buds off a third. None of these several 
bodies is found to jiass into the cytoplasm. Similar budding processes 
have been seen in vegetative cells near the stem apex. No centrosome 
appears in any mitosis, including the last. After the final division, several 
bodies are cut off from the nueleole of the “spennatid”, one of which, 
Wilson thinks, beeomes the blepharoplast. The results of his study of 
Atrichum undulatum are similar, except that the ehromosome number is 
larger (sixteen or seventeen), and that a small body is apparently cut off 
from the nueleole in the prophases of every antheridial division. 
The moss egg seems to have been first seen by Valentine (1837), 
who describes and figures a “solitary cell” lying at the base of the canal 
of the “pistil” of Bryum ligulatum. This cell is oval, transparent and of 
firm texture, and contains a quantity of moving particles which escape 
if the cell is broken. 
Hofmeister (1849, 1851) also finds a large cell witli dense contents 
in the venter of the archegone, from which, soon after the opening of the 
archegone, a group of cells develops that grows into what we now call 
the sporophyte. Hofmeister later (1854 b, 1862) describes for several 
mosses the formation of a “germinal vesicle” within the “central cell” 
of the archegone. 
Schimper (1858) reports that in the archegone of Sphagnum, one of 
the cells of the central row swells considerablv wliile the upper end of the 
archegone is still growing. This “Keimzelle” is either egg- or pear-shaped; 
in the latter case, it is often divided by a wall into an upper narrow -and 
