480 Miscellaneous. 
granulations which they contain not coloured blue, but the paleness 
of the nuclear cavity contrasts strongly with the violaceous ground 
of the protoplasm, which, in this stage, seems to be impregnated in 
a diffuse fashion at once with the methylene blue and the eosin. 
The division-spindles, of which the centrosomes alone have some- 
what more colour, contain neither granules nor chromatic fibrils, 
It is necessary to examine at the end of the first day blastoderms 
with from ten to twelve rows of cells, in order to find, in certain cases 
of karyokinesis, a few extremely minute blue granules, which con- 
stitute the first equatorial plate. It is, moreover, at this stage that 
the protoplasm commences to exhibit the interesting peculiarities 
upon which we shall proceed to dwell. 
From the thirty-sixth hour the methylene blue constantly reacts 
in the manner which we have indicated above. 
Our double coloration therefore renders clearly evident the fact 
mentioned by MM. Henneguy and Sabatier, namely that the nuclei 
of the earliest embryonic stages are difficult to stain; but it has 
enabled us besides to recognize the appearance in the protoplasm of 
the cells of elements to which we attribute great importance, be- 
cause they seem to us to give the key to this peculiarity. Between 
the twenty-fourth and the thirty-sixth hour, when only a few figures 
of division exhibit affinity for the methylene blue, this stain sharply 
distinguishes in the cellular protoplasm certain spherules, of which 
the tint is so much the deeper in proportion as their dimensions are 
reduced. With objectives of high power we perceive that the largest 
spherules differentiate in the interior of their paler mass smaller 
granules of very deep colour, which are marked out within the sur- 
rounding protoplasm. In neighbouring cells it may be observed 
that these granules, whether isolated or arranged in a series, are 
supported by the filaments of an aster: it seems that the latter 
serve to attract them, or, at least, to direct them towards the middle 
of the spindle, in order to furnish the elements of the equatorial 
plate. Henceforth all the cells in process of division will exhibit, 
contrary to what was seen in the first karyokineses, equatorial 
plates which are very distinct and of a vivid blue colour, 
We do not think that the existence of these chromophilous 
granules, representing the earliest conditionin which the chromatin 
substance manifests itself in the cells, has been mentioned before. 
In a memoir upon the development of bony fishes Miecz. von 
Koyalevsky represents the protoplasm of the cells of the blastoderm 
as containing granulations which may be compared with those 
which we are describing, but which are designated by him vitelline 
granulations (“ granulations vitellines”). Owing to the fact that 
the investigations of this naturalist were conducted upon other 
material and by the aid of methods different from our own, it is 
impossible for us to discuss the interpretation which he gives to 
these elements. We would merely observe, and we insist upon this 
fact, that in our better preparations, where the chromophilous 
