THALLOPHYTES 51 
that the forms with one, two, or four eggs have been derived from those 
with eight, some of the eggs not developing, but all eight represented 
by nuclei. Both sperms and eggs are discharged and escape from the 
conceptacle. Fucus is remarkable, therefore, not only in the produc- 
tion of eight eggs by the oogonium, but also in the fact that they are 
discharged before fertilization. The eggs float and are surrounded by 
FIGS. 132-136. Fucus: 132, young oogonia among the paraphyses; 133, an older 
oogonium; 134, oogonium beginning to develop the eight eggs; 135, the eggs rounded 
off; 136, the eggs escaping from the oogonium. After THURET. 
swarms of sperms, which have been observed to set them rotating (figs. 
137, 138). The functioning sperm enters the egg, comes in contact with 
its nucleus, and the two nuclei lying in contact gradually fuse. Ap- 
parently the oospore is not a resting cell, but develops a new plant at 
once (figs. 139, .140). 
In following the life history of Fucus it has been found that the number 
of chromosomes, which is doubled by the fusion of the male and female 
nuclei, is not reduced until the gametes appear. Therefore, using the 
number of chromosomes as a test, the whole vegetative plant is the 
