151 
Secondly, it is well known that in the normal state, and with the 
best methods known, careful observers have not been able to detect the 
centrosome in these cells. Among others the names of FLEMMING and 
von LENHOSSEK may be mentioned. 
Also the nucleus is not indented on the side nearest this struc- 
ture as it usually is in nerve cells possessing a centrosome. 
The peculiar form of the crystal is due, I believe, to the fact that 
it has been formed in the paraffin, and by this means the long, needle- 
like and radiating crystals usually found in sublimate preparations have 
been compressed into the short sectors of a sphere. 
There must be some displacement of the cytoplasm and some 
mechanical, or even chemical change in that protoplasm which re- 
mains in this space after the crystals have been dissolved out. The 
concentric arrangement of the cytoplasm around the disk is probably 
due to the radial pressure of the growing crystals. 
One fact I cannot explain and have no hypothesis to cover, namely, 
that the crystals should always appear in the same position in the cell, 
This would indicate some difference in the constitution of the cell at 
this point as I cannot suggest any mechanical explanation. 
November 25, 1896. 
Nachdruck verboten. 
Bemerkungen zu einer Arbeit tiber die Retina von 
RAMON Y CAJAL!). 
Von E. Kattrus in Göttingen. 
In seiner neuesten Veröffentlichung über die Retina unterzieht 
Ramon Y CAJAL meine Untersuchungen über die Netzhaut der Säuge- 
tiere (Anatomische Hefte, I. Abt. Heft 10, p. 529—582, mit Tafel 
25—28) einer sehr eingehenden Besprechung. Zu meiner Freude 
kann ich feststellen, daß unsere Ergebnisse zum großen Teil überein- 
stimmen. Bei der Erwähnung meiner Erörterungen über das Vor- 
kommen von Anastomosen zwischen Ganglienzellen etc. beurteilt er 
diese jedoch abfällig, und seine Auseinandersetzungen nehmen einen 
derartig persönlichen Charakter an, daß ich nicht umhin kann, einige 
Worte darauf zu erwidern. 
1) Ramon y Casar, Nouvelles contributions 4 l'étude histologique de 
la rétine et ala question des anastomoses des prolongements protoplasmiques. 
Pl. XII—XV. Journal de l’anatomie et de la physiologie, Paris, Année 
32, 1896, No. 5, p. 481—543. 
