252 Rickett.—Fertilization of Sphaerocarpos. 
ing together of its contents and a loss of finer structure. Similar changes 
have taken place also in the cytoplasm. The male nuclei in these instances 
have not reached an advanced stage of development, but appear as in the 
three earliest phases of the normal process (sometimes as in Phase 5), save 
that certain irregularities in shape are sometimes evident. The condition is 
illustrated in Fig. 25. 
It seems clear that more than one antherozoid penetrates the egg in 
a fairly large proportion of cases. The occasional occurrence of polyspermy 
is perhaps connected with the rapidity with which the antherozoids reach 
the egg, and with the delicacy of the membrane of the latter. It seems 
clear also that the entrance of more than one antherozoid disturbs the 
normal process. The male nuclei themselves are arrested in development 
at an early stage, and the egg later undergoes degeneration, in much the 
same way as when it is not fertilized. There is a possibility, however, 
suggested by some of the above-described cases, that one antherozoid may 
continue its development in a normal way while the other remains in a con¬ 
dition characteristic of an earlier phase and finally breaks down and 
disappears. In any case, it is safe to conclude that never does more than 
one male nucleus take part in the formation of the zygote nucleus. 
In many animals polyspermy is a normal occurrence. In other animals 
the entrance of more than one spermatozoon may be induced by various 
means ; such artificial polyspermy usually causing a degeneration of the egg 
nucleus. In plants, however, polyspermy has been reported, so far as 
I know, only in F?icus vesiculosus , by Farmer and Williams ( 1898 ), and in 
Onoclea struthiopteris , by Mottier ( 1904 ). Farmer and Williams noted 
polyspermy in only three cases of a thousand studied. Their figure shows 
two antherozoid nuclei apparently fused with the egg nucleus. In Onoclea 
Mottier figures two antherozoids, one penetrating the egg nucleus in the 
normal way, the other lying coiled in the cytoplasm, surrounded by 
a clear area. 
Cytoplasmic Radiations and Granules . 
The cases that have been mentioned from time to time in the descrip¬ 
tion, which show more or less regularly radiating rows of granules in the 
cytoplasm of the egg, are brought together in Table III. They appear only 
infrequently—in about 6 per cent, of the total number of cases observed— 
and in several different phases. 
These granules are of spherical or ovoid shape, of considerable size, and 
seem to be, at least in many cases, united by fibres. The latter fact, as well 
as their general appearance, makes it improbable that they are of the nature 
of starch grains. They stain violet in the triple stain. In preparations 
stained with iron-alum-haematoxylin and light green, they appear as 
hyaline spheres, quite clear when in focus, black when out of focus. 
