456 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VoL. VI. 
of quite another order than that already referred to. In this species the 
demarcation of the central body from the coloured, peripheral zone is not 
sharp and definite, the one passing gradually into the other. 
In the peripheral, coloured zone the details are more difficult of 
observation. One can indeed see granules, but their relation and the 
distinction between these and portions of the protoplasmic trabeculz 
are difficult to determine in the fresh condition. Ifa fresh specimen of 
O. princeps, O. Froehlichit or O. natans is observed under the apochro- 
matic I. mm. and compensation ocular 8 or 12 with best light (that 
from a white cloud), one can see in the very uppermost plane of the 
cell the membrane studded with refracting points which, when the tube 
of the microscope is slowly lowered, resemble granules, but at the sides 
and ends of the cells they appear as elongated elements which radiate 
from the central body. The refracting points are, therefore, really the 
terminals of protoplasmic trabeculze which connect the central body with 
the membrane. At certain positions of the objective these trabecule 
appear colourless, but at others they have a green tinge which may be 
due to the reflection of green from the colouring matter. Whether the 
latter is in the substance of the trabecule or in the fluid held between 
them it is impossible to say. There are, however, as will be seen after- 
wards in the description of the structure of the hardened cell, indications 
that the blue-green mixture is held in the cavities between the trabecule. 
On the other hand I have never seen granules holding chlorophyll such 
as Hieronymus describes. Of the occurrence of a special chromatophore 
in any form there seems to be not the slightest indication found in the 
living cell. I regard the granules, which to Palla appeared to contain a 
mixture of chlorophyll and phycocyan, and the granules observed by 
Hieronymus as optical transsections of the protoplasmic trabeculz which 
extend from the central body to the cell wall. I have never found these 
trabeculz formed of other than homogeneous substance and can, there- 
fore, not support the view of Hieronymus that coloured granules are 
imbedded in numerous parallel fibres which run in a spiral fashion in the 
coloured zone about the long axis of the cell. I have never observed 
what Palla confidently asserts, namely, that the pigment granules are 
arranged in rows. 
In the outer or peripheral zone there occurs a large number of granules 
which do not contain any colouring matter, although they may at times 
be so situated in the coloured zone as to appear coloured, this being due 
to their reflecting the blue-green of the surrounding cytoplasm. In the 
spores of Cylindrospermum majus large granules imbedded in the sub- 
stance of the peripheral zone, and by their presence forming bays in 
