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J. Ramsbottom, 
deeply-staining thickenings. The first stages of division resemble some¬ 
what the synaptic knot of higher plants but Barrett does “not believe 
that to be their nature”. The chromosomes become massed together into 
a large, deeply staining body from which the spindle appears to emerge. 
There is no indication of centrosomes or of any structure which would 
suggest nuclear polarity. 
This account recalls what Löwenthal recorded in Zygovhizidhim 
Willei (1905) where however the sexual organs are uninucleate and a 
copulating tube is put out from the smaller an theridium. 
One of the Archimycetes in which a sexual process has long been 
known is Polyphagus Eiiglenae. Wager (1898) gave a brief account of 
the structure of the nuclei and of their behaviour during the formation 
of the zygote. Dangeard (1900) confirmed in general these results. 
Wager (1913) has again studied the cytology of the fungus. Reproduction 
takes place by the production of zoospores in sporangia, which may be 
formed on the ordinary vegetative cells, on cysts, or on the sexually 
produced zygotes. The thallus is unicellular and uninucleate, and is 
provided with delicate pseudopodia which penetrate the Euglena cells. 
The structure of the resting nucleus differs somewhat from the normal 
structure in the higher plants and recalls what was described by Percival 
in Synchytvium endobioticum. There is an arc-shaped nucleolus and a 
central, more or less spherical, lightly staining hyaloplasm connected to 
the nuclear membrane by delicate radiating threads. The nucleus is sur¬ 
rounded by a mass of deeply staining chromidia. In the nuclear divisions 
in the zoosporangium a large portion of the nucleolus is extruded into 
the cytoplasm, only a small part being retained for the formation of 
chromosomes. The zoospore possesses a single cilium at the base of 
which is an oil drop in close connection with the nucleus. A chromidial 
mass surrounds both the latter and appears to be continuous with the 
cilium. The zoospore germinates immediately. Sporangia are formed as 
outgrowths of vegetative cells, cysts or zygotes according to nutrimental 
conditions. Cysts resemble smooth-walled zygotes but contain a single 
nucleus. The zygote is formed by the fusion of two ordinary vegetative 
cells which, instead of producing zoosporangia, become transformed into 
gametes. The gametes are usually different in size, the smaller one 
functioning as the male, the larger one as the female. The zygote wall 
may be either spiny or smooth, the former apparently being the normal 
form. No difference was noted in the formation of these. This is in 
agreement with Dangeard's observations though opposed to those of 
Nowakowski (1876). The male gamete puts out a delicate copulating 
pseudopodium-like process which, in contact with the female cell, swells 
and produces the zygote. “Immediately following the appearance of the 
zygote, the protoplasmic contents of the male cell pass through the deli¬ 
cate pseudopodium into the zygote. A perforation appears in the wall 
between the young zygote and the female cell and the contents of the 
latter pass through it into the zygote 1 ).” 
The nuclei of the fusing gametes have exactly the same structure as 
those of the ordinary vegetative cells. The male nucleus is usually smaller 
1) Dangeard, in describing the formation of smooth-walled zygotes states that 
the female nucleus ordinarily passes in first, then the male. 
