ICO 
H aecker. — The Reduction of the 
1 3, 14) and of the embryo-sac-mother-cell (Figs. 50, 52, 54) of 
L ilium Martagon , differ considerably, as every botanist will 
agree, from the figures shown in other divisions of plant-cells. 
Every one who has studied the phenomena of maturation in 
Arthropods, the changes of the chromatin in the germinal 
vesicle and the processes preparing the formation of the 
tetrads, thinks involuntarily of these observations while con- 
templating Guignard’s figures 1 . And so I believe if a true 
reduction of the chromosomes takes place anywhere in the 
generative cell-cycle of plants it must exist there. At all 
events the zoologist is justified in doubting if all possibility 
of misinterpretation of the results obtained by the botanists is 
excluded, as Strasburger believes, at least so long as we are 
presented only with botanical investigations, which are inter- 
preted without knowledge of the newer zoological facts. 
The second question which has been mentioned seems to 
be already solved. Divisions in which a diminution of the 
number of the chromosomes takes place during the resting- 
stage of the nucleus are well known to zoologists, at least 
they occur in embryonic cells, and chiefly in the generative 
cell-cycle. But it has been already shown, at least in several 
cases, that the reduction of the number of chromosomes is 
only apparent ; that is to say, it could be demonstrated 
that during the prophase pairs of elements remain joined one 
with the other, and that they are only separated in the later 
stages. After this phenomenon had been established for 
special cases, it was easy to regard other divisions also in 
which half the number of chromosomes appears, chiefly the 
so-called ‘heterotypic’ divisions, as ‘ plurivalent ’ divisions; 
that is to say, as divisions in which each element is composed 
of two normal elements. I made this attempt some time ago, 
and vom Rath and Riickert have accepted this assumption. 
Riickert has proposed for such cases the term ‘pseudo- 
reduction.’ It would be too detailed to prove that assumption 
1 Compare J. Riickert, Zur Eireifung bei Copepoden, tab. XXI-XXII (Ovo- 
genesis in Cyclops strenuus). 
