1898-99. | ON THE CYTOLOGY OF NON-NUCLEATED ORGANISMS. 459 
body is the homologue of a nucleus is another question which must be 
determined, not only on structural but also on micro-chemical grounds. 
There is not, as already pointed out, a distinct line of demarcation 
between the central body and the peripheral cytoplasm. There is also 
nothing to indicate the occurrence of a membrane about the central 
body. Further, no elements can be found in the central body which 
correspond to the chromatin nodules or “ nucleolar” structures, although 
as will be shown below, granules of a chromatin-like substance obtain in 
the more peripheral portions of the central body, but rarely in the central 
portions of the latter. It must also be pointed out that no observer, 
with the exception of Scott, has described any structures in the 
Cyanophycee which correspond to those found during mitosis in the 
higher organisms. This latter fact, perhaps, taken by itself does not 
count much against the view that the central body is the homologue of 
a nucleus, for; as Biitschli points out, the macro-nucleus of Infusoria 
never exhibits mitotic division, but, taken in conjunction with the other 
facts regarding the structure of the central body, renders it exceedingly 
hypothetical that the central body corresponds to the nucleus of the 
higher organisms. 
From the micro-chemical point of view the evidence for Biitschli’s view 
would appear to be somewhat stronger. I have already pointed out 
elsewhere’ that the substance of the central body gives indications of the 
presence of a compound containing “ masked” iron. Further observations 
on a number of the larger Cyanophycee confirm this. Trichomes of 
Osctllaria Froehlichit, Tolypothrix tenuis, Cylindrospermum mazus, 
hardened in alcohol, mounted on a slide in a mixture of glycerine and 
ammonium hydrogen sulphide and kept in atemperature of about 60°C, 
gave, after some days, preparations in which one observed a somewhat 
dark-green tint in the central body. Very often when the preparation had 
not been a success the result was due to the slow penetration of the 
sulphide which can only act successfully when the reagent attacking 
the iron-holding body can be quickly renewed. The iron reaction, 
when it is obtained in this way, is distinct and does not occur in 
the peripheral zone. The iron reaction may, however, be obtained more 
readily in another way. If the trichomes, hardened in alcohol, are 
placed for two to five hours at 35° C. in sulphuric acid alcohol (acid 
4 vols., alcohol, ninety-five per cent., 100 vols.), and then after washing 
in ninety-five per cent. alcohol, are treated with the acid ferrocyanide 
mixture (potassium ferrocyanide, 1.5 per cent. solution, hydrochloric acid, 
1 “On the Distribution of Assimilated Iron Compounds, other than Hzmoglobins and Hzmatins, in 
Animal and Vegetable Cells,’ Quart. Journ, Micro. Science, Vol. XXXVIII, p. 175. 
