Miscellaneous. 481 
granules are intensely stained by the blue colour, the vitellus is 
perfectly colourless, and that it is impossible to consider these 
granules as vitelline elements, since the methylene blue solely 
affects chromatin in an active condition, as we have already stated. 
Conciusions.—1. In the first stages of development in the dace the 
blastoderm-cells exhibit no individualized chromatin, and the karyo- 
kinetic figures are exclusively formed of achromatic elements. This 
important fact furnishes support to the opinion which the most 
recent researches tend to make the prevalent one, namely that in 
the cell the essential réle does not belong to the chromatin, as was 
formerly believed, but must rather be ascribed to the centrosomes. 
2. The chromatin at first ewists in a diffused condition in the 
protoplasm, as certain authors have stated. It becomes differentiated 
and indwidualized in this protoplasm in the form of granulations 
which can be stained by means of reagents ; then it becomes incorpo- 
rated into the nuclei to constitute the equatorial plates which are absent 
in the first stages.— Comptes Rendus, t. exvil. no. 16, October 16, 
1893, pp. 521-524. 
On the Cerebral Nuclei of Myriopods. 
By M. Joannes Cuarin, 
It is well known how much interest attaches at the present time 
to the study of the elements of the nervous system in Invertebrates. 
By putting into precise form the results thus obtained by zoological 
histology, and contrasting them with the facts revealed by histogeny, 
we shall succeed in elucidating and interpreting exactly the compa- 
rative structure of the nervous tissue, with respect to which so 
many points still remain obscure or imperfectly understood. 
One of these points is the notion of the cerebral nuclei, ganglionic 
nuclei, &c., which have been stated to occur in the Articulata, 
and especially in the class Myriopoda, where, in the accounts of 
various investigations, mention has been made under this name of 
elements which are represented as formations of a special character 
and of high functional value. It is, however, only necessary to 
compare these descriptions in order to prove that they apply, in the 
respective cases, to different elements, the importance and inde- 
pendence of which henceforth become somewhat doubtful. 
Since, therefore, it was imperative that the subject should be 
re-examined in a rigorous fashion, I undertook with this object a 
series of researches which were devoted especially to various species 
of the group Chilopoda (Lithobius forficatus, Scolopendra morsitans, 
Scutigera coleoptrata, &c.). I purposely chose these types because 
they had been mentioned as exhibiting the cerebral or ganglionic 
nuclei with exceptional distinctness. 
Ann. & Mag. N. Hist. Ser. 6. Vol. xii. 36 
