1906] © SIMONS—SARGASSUM FILIPENDULA 177 
two oocysts which contained eight eggs was an old conceptacle, from 
which other sexual elements had apparently long been discharged. 
The eight together were smaller than one normal mature egg. The 
other oocyst which contained eight eggs shared a conceptacle with two 
normal oocysts. It was attached in the side of a conceptacle near the 
surface of the plant, which for a slight distance was modified in struc- 
ture as if in response to an injury. — It is possible in this case that the 
wound incited the reversion.. The appearance of an oocyst contain- 
ing more than one egg in Sargassum must be regarded as a rare rever- 
sion to the Fucus type. 
The resting nucleus of the oocyst is always large, but varies in 
structure. Sometimes it has few granules and no conspicuous reticu- 
lum, whereas at other times it contains many. granules and a dense 
network. The nucleolus is also large in size and variable in structure. 
At the present time no suggestion can be made to account for the 
changes in nuclear structure, excepting that they are the concomitants 
of growth and varying nutritive conditions. 
The method of discharge of the egg from the conceptacle of Sar- 
gassum is somewhat unlike that reported in Fucus and other genera. 
In Fucus the outer membrane of the oocyst remains attached to the 
conceptacle, as explained by THuRET, and the eggs escape in a group 
surrounded by a very delicate inner membrane. In Sargassum the 
entire oocyst becomes freed from the conceptacle and escapes. In 
Fucus the inner membrane dissolves or breaks, thereby freeing the 
naked eggs which it has enclosed. In Sargassum the wall of the oocyst 
‘swells, stretches, and sometimes ruptures, but it may persist for a long 
time, even enveloping later a many-celled sporeling formed within it. 
The inner membrane enclosing the eggs of Pelvetia is separated from 
the outer as in Fucus. In Pelvetia, however, as figured by THURET, 
this membrane persists about the eggs, apparently offering no great 
resistance to the entrance of sperms. Whether the sperm enters the 
egg of Sargassum through a break in the oocyst membrane, whether it 
passes through the membrane, or whether the eggs develop par- 
thenogenetically, isnot known. A study of fertilization in Sargassum 
is surrounded by serious technical difficulties because both eggs and 
sperms develop upon the same plant, thus making it difficult to isolate 
the sexual cell. 
