in Dictyota dichotoma . 185 
contain very small granules similar to those observed every¬ 
where in the framework of the cytoplasm, but in Dictyota 
they are not arranged in a definite plane to form a cell- 
plate. Their part in the process is secondary. 
If, therefore, we accept the doctrine of a morphological 
differentiation of the cytoplasm, we have in Dictyota a cell- 
plate formed of kinoplasm, which neither exists in the form of 
connecting fibres, nor is its substance conveyed to the cell- 
plate region by such fibres. The possibility is not excluded, 
however, that the kinoplasm may exist in the form of fibrillae 
as claimed by Strasburger, and these fibrillae may constitute 
a fine network, distributed among the alveolae or applied 
to the walls or lamellae of the latter, when its fibrillar nature 
would be obscured; or it may exist in the form of a homo¬ 
geneous fluid, evenly distributed over the firmer framework 
of the remaining cytoplasm, whether the latter be a thread- 
work or alveolar in structure. 
It is the opinion of the writer, therefore, that, in such 
cases as Dictyota and Stypocaidon , the cell-plate or plasma- 
membrane is laid down by kinoplasm which is not diffe¬ 
rentiated in the form of conspicuous fibres, but that it exists 
in one of the forms just mentioned. There is reason to 
believe, also, that in many plants where a visible differentiation 
of the cytoplasm is not manifest, plasma-membranes are 
formed in a similar manner. 
The Chromosomes. 
As regards the question of chromosome-reduction, I am 
able to contribute comparatively little that is definite or 
conclusive. 
The researches of Farmer and Williams and Strasburger 
have shown that in Fucus the reduced number of chromo¬ 
somes appears in the oogonium, while in vegetative cells 
of the thallus twice that number is present. Strasburger (’ 97 ) 
finds that in the first nuclear division in the oogonium the 
reduced number appears, fourteen to sixteen having been 
