Hatal, Centrosome in Nerve Cells. 37 
pathological condition. He said ‘‘Au cours cette infection, le 
centrosome ne reste pas inerte, il semble se diviser en deux, les 
deux centrosomes tendent 4 se separer et A emigrer dans deux 
directions opposées.”’ 
Recently some very interesting papers have appeared con- 
cerning the reproduction of the nerve cells. Avyrrs,! who is 
one of the authors, has summarized the observation made on 
the electric lobes of Torpedo, in his preliminary report, as 
follows: 
‘“(1). Large motor cells (electric lobes), not to be distin- 
guished from the ordinary functional cells except by the size of 
the nucleus and cell-body. 
‘«(2). Cells of the same size as (1) but with two nuclear 
bodies. Both may be close together in the center of the cell 
or widely separated and lying near the periphery of the cell. 
‘«(3). Cells showing an evident constriction of the proto- 
toplasmic body between the nuclei as though about to divide. 
‘*(4). Double cells with short connecting bar which 
are usually large and band-shaped. 
“©(5). Double cells in which the connecting bar is drawn 
out into a thin filament, tapering conically from either cell-body 
towards the other. | 
‘©(6). Since each nerve cell of the brain and ganglia has 
a perilymphatic capsule surrounding it, when the cell-body is 
cut into two the perilymphatic space is not at once doubled but 
the two cells still lie in a common cavity. - Because of this it is 
possible to trace the genetic relation of these electromotor cells 
even after they have completely separated by the breaking of 
the connecting bands, as in those cases where the nerve cells 
become completely separated. Ultimately, of course, the lym- 
phatic spaces divide also by completing the capsular wall close 
about each cell.” 
The writer has noticed the same appearance as those de- 
scribed by Dr. Ayers. Here, however, arises the very diffi- 
cult question of interpretation, whether these cells which are 
7 AveRS, H.—Loc. cit. 
