1898-99. } ON THE CYTOLOGY OF NON-NUCLEATED ORGANISMS. 463 
pheral zone is given agreen stain. A similar result has sometimes been 
obtained with Ehrlich’s hematoxylin in dilute solution, but in this case 
the central body takes a blue violet colour. When alcohol and ether 
were employed after the gastric juice the green reaction was not ob- 
tained, and this was the case also when the digested trichomes were 
treated with weak alkaline solutions, this showing that the substance 
which stains green is soluble in alcohol and alkalies. Far oftener, how- 
ever, another condition was observed. Digestion of trichomes for two 
or three days resulted in the production of somewhat irregular masses of 
brownish material placed frequently adjacent to the transverse septa. 
In Osctllaria tenerrima there may usually be only one such mass in each 
cell, being flattened and situated next to either the lateral membrane or 
one of transverse septa. In Mecrocoleus terrestris the corresponding 
brown substance is in the form of granules, many of which are distributed 
through the cell. In all cases the substance forming these masses is 
soluble in alcohol and in weak alkalies. The masses may also take, after 
a prolonged stay in picrocarmine solutions, a dull green or bright green 
colour. Their solubility in alcohol and weak alkaline solutions, their 
absence when the whole of the peripheral layer stains green with picro- 
carmine, and their reactions with the latter dye, appear to indicate that 
they are derived from a constituent uniformly distributed throughout 
the peripheral zone in the living cell. The green reaction under the 
influence of picrocarmine indicates a chromogenic character and it is 
probably a derivative,through digestive action,of one of the constituents 
which form the “ blue-green” of the peripheral zone. 
The occurrence of such a pigment, if it is derived from the colouring 
matter of the cell, unsoluble as it is in water, renders it probable that the 
colouring matter during life is dissolved for the most part in the cavities 
of the vesicles of the peripheral zone. If it were dissolved in the 
cytoplasmic framework it would be difficult to explain its occurrence, 
after digestion, in masses. 
The question of the occurrence of a chromatophore has been dealt 
with in various ways by the majority of investigators of the structure of 
the cell in Cyanophycez. Whatever is meant by the term chromatophore, 
it is necessary to point out that such an organ as it obtains in the more 
highly specialized Alge can never be found in Cyanophycee. All who 
have claimed that a chromatophore is present in the Cyanophycez are 
not agreed as to its character. According to Deinega it is a perforated 
plate, the trabecule of which carry the colouring matter and run parallel, 
in the greater number of cases, with the trichome. In Zukal’s view the 
coloured, peripheral zone is the chromatophore which he claims is finely 
