TRANSACTIONS OF SECTION K. 1021 
2. On the Heterotype Divisions of Lilium Martagon, By Erne Sarcanr. 
There are two series of nuclear divisions in the life-history of Lilium Martagon 
which exhibit twelve chromosomes in place of twenty-four. 
I. Spermatogenesis :— 
1. First division of pollen mother-cell nucleus. 
2. Second division of pollen mother-cell nucleus. 
3. Division of pollen-grain nucleus into vegetative and generative nuclei. 
4. Division of generative nucleus in pollen-tube. 
IT, Odgenesis :— 
1. Division of primary embryo-sac nucleus into micropylar and chalazal 
nuclei. 
2. Division of micropylar daughter nucleus. 
3. Division of both daughter nuclei of the micropylar nucleus. 
My preparations include the whole odgenetic series and the first three divisions 
of the spermatogenetic series. The second and third divisions in both are precisely 
similar to vegetative nuclear divisions except in possessing only half the number of 
chromosomes. They are called homotype. 
The first nuclear division on either side is called heterotype, because the process 
of karyokinesis differs from that of the vegetative nucleus. The chief points which 
distinguish it are :— 
1. The resting nucleus, after some increase in size, passes into a contracted state 
called synapsis. 
2. The chromatic ribbon of the spirem is not homogeneous, but is composed of 
an erythrophilous ribbon bearing a double row of cyanophilous dots. 
3. Longitudinal fission appears in the spirem ribbon before its division into 
chromosomes. 
4, A second longitudinal fission appears in each segment of the immature 
chromosomes. 
5. The segments of each chromosome are tightly twisted on each other, and 
separate from near the middle or fromeither end. The untwisting of the segments 
from each other as they separate gives a contorted appearance to each chromosome 
of the nuclear plate, and adjacent chromosomes are otten of totally different shape. 
The appearance of the heterotype spindle is therefore much less regular than that 
of the homotype spindle. 
6, The chromosomes of the diaster stage are usually V-shaped. 
3. On the Cells of the Cyanophycee. By Professor E. Zacwartas. 
My recent researches on the Cyanophycee have confirmed and extended my 
former statements. Cell protoplasm, containing the coloured matter, surrounds a 
central body which is colourless. This body is not homogeneous in the living state ; 
when treated with reagents, it shows apparently a spongy structure ; in its sur- 
face, in eertain cases outside of it, are distributed granules of different shape and 
size, becoming deeply stained, when treated with methylen-blue. These granules 
(‘Centralsubstanz,’ as I have named them formally) agree, as stated some years 
ago, in their reactions with the chromatin of the nucleus of other organisms. 
However, I recently found slight differences, which, combined with certain con- 
siderations, render it doubtful whether the ‘Centralsubstanz’ contains nuclein like 
the Chromosomes or not. 
Iodine reactions observed in Gloiotrichia pisum render it probable that the 
central body of the spore and of those cells immediately above it contains glycogen. 
The cell protoplasm contains in different stages of cell-life different quantities of 
granules, which are chemically different from the central substance. Both kinds of 
granules are stored in the spores of Gloiotrichia. 
By certain methods of culture the granulations can be made to vanish entirely 
out of the cells. 
