Cytology of a new variety of A chlya amevicana . 165 
division. Why should the number of nuclei be doubled, when 
it is already ten times too great, if the final reduction in 
number is to be brought about by simple fusions, four times 
repeated ? This question of wholesale nuclear fusions is one 
which we expect to see proved conclusively by actual demon- 
stration. It is so improbable in itself at any stage in the 
life-history of a plant that we may be pardoned in the absence 
of such demonstration for unbounded scepticism as to its 
occurrence. 
But Hartog’s theory, even as a theory, has an unsound 
foundation. Consider what it means. The nuclei in question, 
surrounded by their protoplasmic masses — energids, let us 
say— -are female gametes and very highly developed ones too. 
So far as external differentiation goes, the evolution of sex 
in the Saprolegnieae has been carried to an extreme. The 
theory, then, is that of the multiple endogamous union of 
highly developed female gametes in plants where very dis- 
similar male gametes are thoroughly well known. Imagine 
a botanist broaching as a theory the multiple union of Fucus- 
eggs to form a zygote and the universal incredulity with 
which it would justly be met, and we have some idea of the 
great improbability of Hartog’s theory. Let us put the 
matter plainly : — a variation from the ordinary mode of fer- 
tilization so great as that propounded in this theory needs 
to be supported by evidence overwhelming in quantity and 
perfectly satisfactory in quality. 
What is the evidence adduced by Hartog in support of 
his theory? It is furnished by the clusters of chromosome- 
like bodies represented in his Fig. 40, and in Fig. 42 of the 
present paper. His interpretation of these figures is that 
each granule is the representative of the central body of one 
of the original resting nuclei, and he states that the number of 
these granules varies from four to twenty : a figure with four 
granules represents four or more fused nuclei, one with twenty 
granules, twenty or more nuclei. The granules get fewer 
by fusing with one another, but as they do not get larger 
they must lose substance in some way which he has not yet 
