Notes. 
481 
In spite of repeated attempts, we have not succeeded in observing 
the first nuclear division in the oogonium, but the later ones have 
been seen both in Fucus vesiculosus and in F. platycarpus , in which 
eight oospheres are formed. Oltmanns asserts that in Ascopliyllum , 
in which only four oospheres are commonly formed, eight free nuclei 
occur at an earlier stage, but that four of these ultimately abort, and 
do not become centres of cell formation. Our observations tend to 
confirm him in this respect, but we found that in some cases a fifth 
oosphere, smaller than the rest, was occasionally differentiated, and 
that when freed from the oogonium it exerted an attraction on the 
antherozoids just like its larger sister oospheres. 
When an oogonial nucleus is about to divide, it first becomes 
slightly, then very much, elongated so as to resemble an ellipse. Fine 
radiations are seen to extend from the two ends into the surrounding 
cytoplasm. The latter is at first tolerably uniformly granular, but as 
the radiations around the polar areas increase, these regions become 
cleared altogether of the granules which then become massed outside 
them. The nucleus rapidly becomes more spindle-shaped, and its 
chromatic elements are chiefly grouped near each pole, leaving a clear 
space about the equator in which the nucleolus is situated. In this 
respect the nuclei of Fucus offer a striking contrast to those of Pellia 
epipliylla already described (Annals of Botany, vol. viii. p. 221) by 
one of us. In the latter plant the chromatic portion of the nucleus 
assumes an equatorial position at the corresponding stage in division, 
while the polar regions are clear. 
The polar radiations continue to increase and the nucleus to 
lengthen, until the entire structure recalls the figure of a dumb-bell, 
in which the nucleus answers to the handle, and the radiation areas 
to the knobs. If the radii be traced outwardly, they are seen to 
terminate either in the frothy protoplasm, on the angles where the 
foam walls meet, or on the large granules which surround the cleared 
areas and are embedded in the foam. This point is one of con- 
siderable importance, and we shall revert to it further on. No struc- 
tures were seen which could certainly be identified as centrosomes, 
although bodies suggestive of them were often observed ; but these 
proved to be so variable in size and position, as well as in number, 
that we feel unable to attach any special significance to them. 
The next stage in the mitosis is that in which the interpolar spindle 
arises, with the chromosomes disposed upon its equator. The spindle 
