708 Sargant.—Recent Work on the Results 
tissue. In the case we are considering, we have a triple 
fusion which unites in a single nucleus a mass of chromosome- 
substance at least twice as great as that found in an 
ordinary somatic nucleus. The body formed by repeated 
division of this nucleus is small and short-lived, though from the 
presence of male and female elements in the combination we 
might almost have expected the formation of a second embryo. 
It is difficult to avoid the suspicion that the presence of the 
third nucleus with its redundant chromosomes serves to secure 
the degeneracy of the resulting tissue. This hypothesis does 
not depend on any view as to the race-history of the fusion. 
If it is historically a fertilization the third nucleus may have 
been introduced to maim the second embryo from the begin¬ 
ning, and secure the survival of the first without a struggle. 
Its value as a food-body would secure the persistence of the 
abortive embryo in the shape of the tissue we call endosperm. 
If, on the other hand, the second generative nucleus served 
from the outset merely as a signal to one of the polar nuclei 
that fertilization had been accomplished, and that it was 
time for prothallial formation to proceed, the intrusion of a 
third nucleus would be necessary to prevent the formation 
of a second embryo as a consequence of the signal. 
Although the question now under discussion is purely 
physiological, its solution would undoubtedly be forwarded by 
anyadvance in our knowledge concerning the originof the triple 
fusion. This is another very strong reason for the investigation 
of anomalous embryo-sacs in the hope of hitting on primitive 
forms. If the first endosperm-nucleus is formed by a nuclear 
fusion which has once been a normal sexual union, it must now 
be considered as a more or less degenerate act of fertilization, 
and the question whether it has retained enough of its original 
nature to still deserve the name of fertilization is a com¬ 
paratively simple one. But if such morphological research 
should show that Strasburger’s view is justified, that the 
generative nucleus has never been a fertilizing agent, but has 
served merely as a signal for the further development of the 
prothallus, the process will appear in a different light. The 
