306 DR THOMAS H. BRYCE ON 
The centrosome is a large body, which stains a delicate grey in iron hematoxylin” 
preparations, many degrees lighter in tint than the intensely black centrosome of 
the dividing erythrocytes. In sections counterstained with eosin the body is red, 
It does not stain, therefore, like the chromatin. In methylene blue and eosin 
preparations it is very faint, coming only very indistinctly out as a slightly darker 
area on the faintly bluish-red protoplasm. In triacid preparations it is very distinct 
(fig. 31, Pl. IIL, and fig. 48, Pl. V.), and has a neutral tint. I have never seen in my 
material any finer structure within the centrosome, nor can I make out any oranules, | 
single, double, or multiple. I have therefore not adopted the term microcentum 
(HEIDENHAIN),* but have used the word centrosome in Boverr’s sense. ‘ 
Round the centrosome there is a sphere distinctly radiate (as Van BENEDEN, 
HEmENHAIN, and others have described), bounded by a circle of microsomes. This 
separates the central from an astral zone, into which the fibres of the central sphere 
pass. There are no outer circles of microsomes concentrically arranged, as described | 
for some cells (DrRtNeER). The radii are at first straight, then becoming vavy, they 
seem to branch and join the general meshwork (fig. 20, Pl. IL.).t 
In fig. 21, Pl. IL. is represented an amceboid leucocyte. The extended pseudo 
podium is not straight, but wavy, and its axis is occupied by a core of seeming fibrille | 
passing from the centrosome. The cytoplasm around this central core shows an 
exceedingly delicate meshwork structure, but it is difficult to be quite sure of this 
towards the end of the pseudopodium, which is not well defined, and composed of 
very delicate substance. From the centrosome to the sides of the nucleus there | 
seems to pass a core of seeming fibrillee, represented m the section by the two lateral | 
strands figured. | 
Another wandering cell is drawn in fig. 26, Pl. IV. It is passing throuehill a 
space between a number of other mesenchyme cells. The manner in which | . 
polymorphic nucleus is doubled up is interesting. The meshwork and radiations as a 
well as the centrosome are very obscurely revealed in these granular cells by methylene 
blue and eosin, but it could be made out that at the extremity of the body the mesh- 
work was drawn out, and that delicate radiations from the centrosome passed into it. 
Fig. 22, Pl. II. represents a corpuscle in which the centrosome has divided. The 
‘attraction sphere’ has apparently enlarged, and is not now bounded by a circle of 
microsomes. Round the two centrosomes new radiations are developing within the old 
sphere, which has now the appearance of an extremely fine feltwork; so fine that it 1s 
difficult to convince oneself that there is any structure at all. | 
The protoplasm of these leucocytes is basophil when free from granules; when | 
only a few granules are present, it stains a delicate warm blue with methylene 
blue and eosin, and shows a very delicate faint meshwork. The granules | 
colour intensely with eosin, are copper red after treatment with  triacid, and | 
blacken after iron hematoxylin. They vary in size in the same cell and im | 
* Archi f. mkr. Anat., Ba. xliii. + Cf. Gulland, Jour. of Phys., vol, xix. 
