Neomeris dumetosa, L amour. 603 
collect at the distal ends of the segments, and the elongated 
pedicels of the cortical segments as also those of the aplano- 
sporangia will be practically devoid of corpuscles ; while, on 
the other hand, the dilated cortical facets and the spherical 
aplanosporangia will appear furnished with a dense layer 
(Fig. 26). 
Nor will streaming movements of the protoplasm, entraining 
the corpuscles, bring about any great change in their distribu- 
tion. The perforated septum being concave towards the 
cavity of each segment, revolution will take place around 
rather than through the pore ; hence, although the corpuscles 
may accumulate at the distal ends of the basal segments 
(Fig. 2 6), few will pass on into the pedicels of the cortical 
segments ; and for the same reason, the narrower the pedicels 
become, and the more spherical the cortical facets and aplano- 
sporangia, the fewer corpuscles will pass inwards. Exact 
demonstration of the behaviour of the chlorophyll-corpuscles 
is of course out of the question with spirit-material ; but the 
observations of De Bary and Strasburger 1 on the aggregation 
of the chloroplasts in young non-calcified plants of Acetabularia, 
due to their extreme sensitiveness to direct sunlight, lend 
support to the view that extensive movements of the cor- 
puscles may take place in the cortical facets, without leading 
to any considerable migration into the pedicels. Hence the 
absence of incrustation on the pedicels is to be correlated 
with a diminution in the number of contained chlorophyll- 
corpuscles ; and though a slight incrustation was laid down 
on the short broad pedicels of Stage IV (Fig. 21), as these 
become narrow and elongated in Stage V, the absence of 
corpuscles will result in an entire absence of calcification 
(Figs. 26, 30). On the other hand, the abundant supply of 
chlorophyll in the cortical facets does not lead to calcification 
of the outer surface of the thallus, owing to the lack of 
a mucilaginous layer in this locality. 
The mechanism of calcification, so far then, admits of ready 
1 Bot. Zeit. 1877. 
T t 2 
