1895.] Anatomical and Physiological Researches. 225 
and Schaffner (13). Karsten’s theory (10) of the derivation 
of the centrospheres from the nucleoli has been shared by 
Julin and other zoologists; but the source of his error has 
already been pointed out, and the observations of most stu- 
dents of animal cells are equally opposed to this view. 
As early as 1888, Boveri gave the name archoplasm to the 
centrosomes with the surrounding cytoplasm, and this term 
has been more or less loosely used by subsequent writers. 
Strasburger has more recently (15) proposed to distinguish 
that part of the cytoplasm which appears to play an active 
part in karyokinesis, surrounding and including the centro- 
somes, as kinoplasm, from the merely nutrient portion, or ¢ro- 
phoplasm. And this distinction is a very useful one. In their 
morphological application, the terms archoplasm and kino- 
plasm appear to be synonymous. The number of centro- 
deed in the earliest stages of the formation of the daughter 
nucleus which the kinoplasm accompanies. Heidenhain (8) 
finds in some animal cells as many as a hundred granules in a 
group, which he regards as equivalent to a single center. 
But it seems fair to ask if these may not represent pathological 
conditions or artificial products. At all events, no such con- 
dition has been recognized in plants. 
Normal karyokinesis appears to be introduced by the pass- 
age to each pole of the nucleus of a part of the kinoplasm 
with a centrosome, and by the formation, apparently from 
these starting points, of a spindle-shaped frame-work of deli- 
cate fibres. The question as to the source from which the 
material of these fibres is derived has long been a matter of 
dispute. Most zoological writers have believed it to be 
formed chiefly within the nucleus, while most botanists main- 
tain for it an extra-nuclear origin. Flemming now concedes 
that the ends of the spindle originate outside of the nucleus, 
while Hermann and the latest writer on karyokinesis in ani- 
mals, Driiner (4), fully agree with Strasburger in deriving it 
from the kinoplasm. ng eae 
The di t logists ast the spindle 
1 ms a 
WiICtsice 
15—Vol. XX.—No. 5. 
