478 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VoL. VI. 
the preparations are made with picric acid the frequency of these 
shrunken masses is greatly reduced. The cytoplasm then usually 
appears vesiculated throughout and it stains uniformly with hama- 
toxylin, showing an absence of granules. 
When the threads of 4. alba and B. mirabilis, after being hardened in 
alcohol, were treated with the nitric-molybdate reagent for two to three 
hours and then acted upon with a solution of phenylhydrazin hydro- 
chloride of two per cent. strength, in order to demonstrate the dis- 
tribution of organic phosphorus, the latter was found to be uniformly 
diffused throughout the cell. In 4. mzradzlis the condensed portions 
observed in some cells, as already described,gave a marked indication of 
the presence of “ masked” phosphorus, but it appeared so because in the 
shrunken condition to which these masses are due more cytoplasm is 
gathered into a smaller volume than in cells with unshrunken cytoplasm. 
Fig. 61 illustrates this. Ina@ and 6 areobserved two shrunken masses of 
cytoplasm, in these are aggregations simulating granules, while in c the 
cytoplasm shows the organic phosphorus uniformly distributed through- 
out the cell. In &. alba the phosphorus is distributed uniformly with 
the cytoplasm and the method did not reveal the presence of granules. 
The reaction for iron derived from the ‘masked ” condition, is in B. 
alba and &. mirabilis found to be uniform with the distribution of the 
cytoplasm. When sulphuric acid alcohol is used to set the organic iron 
free in the threads and the preparation is washed free from acid with abso- 
lute alcohol and stained with a pure aqueous solution (one per cent.) 
of hematoxylin, the result is decided enough to determine definitely 
that there are no specialized chromatin-holding structures like nuclei or 
like Biitschli’s central body. Granules sometimes found distributed in 
the peripheral portion of the cytoplasm give the reaction. 
The distribution of the “masked” iron being then like that of the 
organic phosphorus, it follows that the substance containing these ele- 
ments, the analogue of the chromatin of more highly specialized cells, is 
contained, not in any nucleus however rudimentary, but diffused in the 
cytoplasm, and sometimes, also, localized in granules. 
Somewhat different are the results of observations on the spirillum- 
like form, and on the “ cocci,’ and comma-shaped organisms. Here, as 
little as in the thread or “leptothrix” forms, is there any evidence of the 
existence of a nucleus, rudimentary or otherwise. In these, the vesicles 
occupied by the sulphur droplets, are all crowded about the centre, or 
about the central axis, leaving the peripheral layer as a thin, homo- 
geneous structure applied to the membrane. In the “spirillum” form the 
