1887] The Significance of Sex. 147 
peared as granules. The nucleus is only a large nodal point in 
the centre, and as this developed it repeated the process, and finally 
the nucleolus in a mature cell takes on the reticulate structure. He 
laid the basis for Nageli’s theory of heredity by advancing the 
notion that the reticuli of all the cells in the body are continuous, 
and so anticipated modern studies of protoplasmic continuity. 
This year is memorable as marking the beginning of studies 
on karyokinesis. The stimulus came from a paper by Schneider, 
in which the different phases were pretty well described, though 
their connection and sequence were unknown. Even the spindle 
and cell plate were figured. Bütschli and Fol confirmed these 
results, the former mainly as to the nuclear rosette and its sepa- 
ration into two halves to constitute.the daughter-nuclei, while 
the latter got the asters and spindle best; hence the former 
agreed with Schneider that there was no deconstitution of the 
nucleus, while the latter inclined to side with the orthodox school. 
Auerbach now appeared with his “Organologische Studien” 
(1874). He starts with Heitzmann’s views as to the organization 
of protoplasm, but considers the nucleus to be a sap-cavity into 
which molecules of protoplasm wander and grow to become 
nucleoli. These multiply by division, so that old cells have many 
nucleoli. The cells of highly-organized tissues, he says, have 
more nucleoli than cells lower in the scale of organization. The 
nucleoli are young cells, and they are simply separated into two 
groups in direct division ; but in indirect division, which he dis- 
tinguishes as palingenetic, these are dissolved into a molecular 
state in the nuclear sap, and then absorbed with the sap by the 
cell-plasma. This process is termed £aryolysis, the spindle with 
its polar asters is the karyolytic figure and the simple expression 
of the streaming out of the nuclear substance. Later, near each 
star, the sap and molecules return to form a daughter-nucleus. 
_ This seemed a pretty fair explanation, and Flemming at this time 
was much influenced by it. 
Bütschli, however (1875), opposed the theory, though he modi- 
fied his former view of the simple persistence and division of the 
nucleus to the view that the nucleus is reconstructed into a spindle, 
at whose equator the fibres become thickened to form the nu- 
clear plate, which plate by splitting passed its halves to the 
poles of the spindle to be re-formed into nuclei. In the same 
© A list of the papers referred to will be given at the close of the article. 
