204. W. WALDEYER. 
objects should be chosen. It would be a good thing were 
scientific meetings, especially those of the recently founded 
German Anatomical Society, more utilised than hitherto for 
bringing to an end such differences, by an exhibition of the pre- 
parations concerned. I note, in opposition to Carnoy’s idea, 
that Strasburger, in his latest memoir (191), agrees with 
Flemming in regarding longitudinal splitting of the mother- 
segments (chromosomes) and the separation of the threads 
arising from such splitting into two daughter-nuclei, as a general 
process, at least in the higher animals and plants, and as the 
highest point of mitotic nuclear division (loe. cit., p. 185). 
Platner (161) indeed, like Carnoy, sometimes found in Lepi- 
doptera a quite irregular separation of chromatin bodies with- 
out a previous formation of an equatorial plate, and without 
longitudinal division. Yet he will not decide whether this 
process must be regarded as normal or as au indication of 
degeneration of the cells concerned. 
At all events we see that, in the present state of the case, 
most authors look upon Flemming’s longitudinal splitting as the 
essential phenomenon of karyokinesis, and, as I believe I can 
say from my own researches, rightly. 
Abnormal conditions are also briefly described by Oskar 
Schultze (183) in confirmation of the earlier work of Bellonci 
(16 d) in the segmentation of Axolotl. Here the thread-skein 
is not brought about by a direct transformation of the threads 
of the network, but by the appearance of small chromatin bodies 
(Pfitzner’s “ Kornchen,” O. Schultze) in the nuclear membrane, 
within which in this object the skein wholly lies ; these later 
on unite and arrange themselves in a series of loops. . 
We have already mentioned that the nucleus, as well as the 
spindle figure arising from it, undergoes a change of position 
during the course of karyokinesis. This is especially distinct in 
the formation of the directive corpuscles (see Part II). The con- 
sideration of these things becomes very important in the study 
of egg segmentation. In reference to the influences coming into 
question here, Pfliiger has alluded to the action of gravity, whilst 
O. Hertwig, in his memoir—“ Welchen Einfluss iibt die Schwer- 
