278 Shaw . — The Fertilization of Onoclea . 
in Fig. 1 and sections of the other eggs on the same slide. 
In Fig. 1 the small end of the spermatozoid is directed 
toward the base of the archegonium. The lower portions 
of two coils were cut off by the razor, and are to be seen 
in the next section on the slide. The sperm-nucleus within 
the egg- nucleus becomes granular and the granules slowly 
separate. Thirty minutes after the entrance of the first 
spermatozoid into the archegonium the sperm-nucleus may 
show traces of the granular structure, as in Fig. 2, but 
usually it is not evident until two hours have elapsed. It 
shows plainly in Fig. 3, from a specimen fixed after three 
hours. Fig. 4, after twenty-four hours, shows little, if any, 
advance in this respect. Fig. 6 , after twenty- four hours, 
shows the sperm-chromatin distributed in one quarter of 
the egg-nucleus very much as it was found in Fig. 9 after 
sixty hours. In most of the preparations the chromatin of 
the two nuclei can be seen distinctly, but in only a few 
cases was the linin also clearly distinguished. Among the 
best of these is one represented in Fig. 12, which was fixed 
in J °/ o chromic acid for twelve hours, washed two days in 
water, one and a half days in dilute sulphurous acid, and three 
hours in water, and then stained with alum-carmine. The 
linin threads connecting and supporting the chromatin 
granules of the female nucleus are especially distinct, and 
had one the time one might almost construct a complete 
map of the network system. In the sperm-nucleus the 
granules and the threads are so closely packed that the 
courses of the threads cannot be followed in detail. The 
sperm-nucleus often retains the spiral arrangement of its 
substance for a long time, as in Fig. 13, after twelve hours. 
It may lose this arrangement early, as in Fig. 7, after fourteen 
hours. Here the larger and smaller end can still be 
identified. In the latest stages in which the sperm-substance 
could be recognized it had become distributed through a 
larger part of the female nucleus (Fig. 9). 
The different eggs fertilized on one prothallium at the 
same time do not have the sperm-nucleus in the same 
