310 BOTANICAL GAZETTE [MAY 
The tip of the antheridial tube at the time of zonation is very 
near if not directly applied to the ooplasm. As it penetrates the 
oosphere a nucleus slips down into the swollen end whose sur- 
rounding wall is later dissolved, and the sperm nucleus is then 
introduced into the ooplasm surrounded by a quantity of dense 
cytoplasm. 
The sperm nucleus approaches the female nucleus and slowly 
fuses with it in close proximity to the coenocentrum. 
The coenocentrum begins to disorganize at about the time of 
the fusion of the sexual nuclei. The dissolution may be accom- 
panied by fragmentation, but the final result is always the same, 
namely an irregular ill-defined region of dense protoplasm in the 
oospore that finally becomes indistinguishable from the surround- 
ing cytoplasm. 
The coenocentrum is not a permanent structure in the pro- 
toplasm. Arising as an accumulation of cytoplasm, it becomes 
most conspicuous at about the time of zonation, finally disap- 
pearing after the fusion of the sexual nuclei. The writer sug- 
gests that it may be merely the morphological expression of the 
remarkable activities displayed by the protoplasm, of the oogo- 
nium as a whole at the time of the differentiation of the oosphere. 
THE UNIVERSITY OF CHICAGO. 
LITERATURE REFERRED TO. 
BERLESE, 98. Ueber die Befruchtung und oe der Oosphare bet 
den Peronosporen. Jahrb. f. wiss. Bot. 31: 150. 
DANGEARD et LEGER, 94. Recherches sur i structure des Murcorinées. 
Le Botaniste 4: 4. 
HARTOG, 95. On the cytology of the vegetative and reproductive organs of 
the Saprolegniaceae. Trans. Roy. Irish Acad. 30: 6 
LEGER, 95. Be py et eee ia de la zygospore du Sporodinia grandis. 
Rev. Gén. d. B 
STEVENS, 99. The aaa oosphere of Adbugo biti. Bot. Gaz. 28: 149- 
SWINGLE, 98. Two new organs of the plant cell. Bot. Gaz. 25: 110 
THAXTER, 95. New or peculiar aquatic fungi. I. Monoblepharis. Bo 
20: 433. . 
WAGER, 96. On the structure and reproduction of Cystopus candidus Lev. 
Ann. Bot. 10: 295. 
t. Gaz. 
