304 KING. [VoL. XIX. 
hematoxylin the masses now appear grayish, and they are 
found to be composed of a meshwork of exceedingly fine 
fibres inclosing several darker homogeneous bodies. In prep- 
arations stained with safranin and gentian violet a much bet- 
ter differentiation is obtained. The meshwork of fibres in- 
variably takes the blue of the gentian violet, while the rounded 
bodies in the interior, which are of various sizes, react differ- 
ently towards the stain; the larger of these bodies, which are 
usually slightly irregular in outline, stain a reddish purple; 
the medium-sized ones, which are rounded and have a smooth 
outline, stain uniformly red, while the very small granules take 
the gentian violet. From the staining reactions of these 
masses, therefore, it is evident that they contain two different 
substances ; fine fibres which are doubtless composed of chro- 
matin not used for the chromosomes, and rounded bodies which 
are nucleoli. 
For convenience in description I shall apply the term com- 
pound-nucleoli to the complex masses shown in Figs. 26-35 
and also to the irregular nucleolar bodies shown in Figs. 39, 
40, 43, 45, etc., reserving the term nucleoli for the smaller 
rounded bodies found in the interior of the larger masses at the 
stage of Figs. 35-36. The nucleoli which stain uniformly red 
with safranin will be called plasmosomes, while those that stain 
like chromatin will be considered karyosomes. In order to 
distinguish the chromatin of the chromosomes from that of 
the meshwork which forms part of the compound-nucleoli I 
shall refer to the former as “‘basichromatin” and to the latter 
as “oxychromatin.” Iam aware that these terms are not being 
used strictly in the sense in which they were introduced by 
Heidenhain (37), since both kinds of chromatin show the 
same color reactions with all methods of staining employed. 
Their use has been considered advisable here, however, in 
order to avoid the introduction of new terms. 
At the stage in the resolution of a large compound-nucleolus 
shown in Fig. 36, the oxychromatin meshwork is much more 
clearly defined than at an earlier period and ‘the threads are 
thicker and more granular. The number of nucleoli found in 
