384 BOTANICAL GAZETTE [NOVEMBER 
number seems essential only in the gonotokonts,’ when it insures the pairin 
of paternal and maternal chromosomes. The chromosomes of a nucleus prob- 
ably differ among themselves, and it is almost certain that the two chromosomes 
of each pair pass to different nuclei. The heterotypic and homotypic mitoses 
differ in that the first distributes to the daughter nuclei the paired, univalent, and 
already longitudinally split paternal or maternal chromosomes, while the second 
separates the longitudinal halves of chromosomes whose longitudinal splitting 
was already prepared during the prophase of the first mitoses. The behavior 
of chromatin in fertilization and in parthenogenesis is discussed in detail. SrRas- 
BURGER’S paper closes with a reinvestigation of the peculiar hybrid, Cystisus 
Adami, showing that there is no cytological basis for the assumption that it is a 
anastomoses and the formation of a continuous spirem, and 5) a uniseriate dis- 
tribution of chromosomes in each thread, the opposition of the chrom 
parallel threads, followed by the fusion of the threads and union of the chromo- 
somes in pairs. : 
MrvakeE®* studied the reduction division in the pollen mother-cells of Galtonia, 
Iris, Lilium, Allium, Funkia, and Tradescantia. In synapsis there is not @ 
pairing of fully formed chromosomes, but of groups of chromatic substance. 
These groups are drawn out into a double thread, which may be re d as 
approximated chains of chromosome pairs. The chromosomes, paired veh on 
early stage, continue to grow as pairs until mature. In the heterotypic mitosis 
the two members of each pair are separated and pass to opposite 
sequently, this mitosis is a reduction or qualitative division. The secon 
is a doubling (Aguationsteilung) division. ; 
ouiae scifi the ieheesiok division most thoroughly in Thal shi 
purpurascens, but for comparison used also Helleborus foetidus, P odophyl 
e term, Gonotokonten, proposed by Lorsy, applies to spore mother cello 
plants and to the primary spermatocytes and primary oocyte animals. = 
9 ALLEN, C. E., Das Verhalten der Kernsubstanzen wahrend der pF Z. 
den Pollenmutterzellen von Lilium canadense. Jahrb. Wiss: Bot. 42: 73-82. ; 
1905 einiget 
10 Miyake, K., Ueber Reduktionsteilung in den Pollenmutterzellen 
Monokotylen. Jahrb. Wiss. Bot. 42:83-120. pls. 3-5- 1995- 
11 OvERTON, J. B., Ueber Reduktionsteilung in den Pollen 
mutterzellen einige 
Dikotylen. Jahrb. Wiss. Bot. 42:121-153- pls. 0-7. 1995- ; 
