382 BOTANICAL GAZETTE [NOVEMBER 
cases in which the so-called vegetative nucleus does not enter into 
the fusion, and still the product is only endosperm. 
STRASBURGER analyzed the situation, and held to the original 
interpretation of the endosperm as gametophytic tissue, on the 
plea that there are two aspects of fertilization, one being fertiliza- 
tion as a stimulus to growth, the other being fertilization as a 
transmission of hereditary characters. These two aspects he 
designated respectively vegetative fertilization and generative 
fertilization. He saw in the result of the triple fusion only a 
stimulus to growth, resulting merely in tissue, and not a trans- 
mission of hereditary characters, which would express itself in an 
organization. Unfortunately for this view, all the phenomena of 
xenia are against it, for in such cases it is quite evident that char- 
acters of the pollen parent are transmitted to the endosperm by 
the male nucleus that enters into the triple fusion, but of course 
there is no sporophytic organization. 
Furthermore, the cytological test for the two generations 
breaks down in this case, as it had in cases of apogamy and apos- 
pory, for the seinen number of chromosomes, in case triple 
fusion has occurred, is neither x nor 2x, but at least 3x. To speak 
of 3x gametophytic tissue is to use some other test than the number 
of chromosomes. It must not be understood that this in any way 
affects the general contrast between gametophytes and sporophytes 
on the basis of chromosome numbers. A generation that follows 
a reduction division is of necessity an x generation; and one that 
follows fertilization is a 2x generation. But when the reduction 
division or fertilization does not occur, and still another generation 
follows, the chromosomes of that generation must become unusual 
in number, following an unusual situation. 
It will be helpful to consider the cases of endosperm formation 
that do not involve triple fusion. This will enable us to recognize 
the fact that the origin of endosperm is not necessarily related to 
the triple fusion, and that we have in endosperm a constant product 
arising from variable antecedents. It is simple to put such cases 
into two categories: (r) multiple fusions, and (2) no triple fusion. 
(1) The well-known case of Peperomia may represent the 
category of multiple fusions. In the fusion of 8-14 nuclei to form 
