220 BOTANICAL GAZETTE [ SEPTEMBER 
third of a cladodium, the one being a direct continuation of the other without 
constriction or articulation. The second case is of a fruit formed within the 
upper portion of a cladodium and swelling the otherwise flat branch as if the 
Ramirez discusses their morphological significance and concludes that al 
three cases strongly support the view that the inferior ovary of the Cactacee 
is axile in nature —FREDERICK LEROY SARGENT. 
BELAJEFF’S recent paper® on the reduction division of the plant nucleus 
is quite a surprise. Haecker intimated in 1895 that the figures of Strasbur- 
ger and Guignard might indicate a reduction division in plants, but the 
efforts of botanists, especially of Miss Sargant, have given only negative evi- 
dence. The zoologist Ishikawa, who studied pollen mother cells of A//ium 
Jistulosum, gives the only report of a reduction division in plants. Strasburger 
and Mottier described such a division in pollen mother cells of Lilium and 
Podophyllum, but almost immediately acknowledged that the work needed 
reinvestigation. Belajeff now comes forward with a genuine reduction divi- 
sion (in the sense of the Freiburg school) in the second division of the pollen 
mother cells of Iris. For evidence he relies upon the shape of the chromo- 
somes, and gives figures illustrating the shape taken by chromosomes in vege- 
tative division, heterotype division, and his reduction division. He claims 
that previous investigators have not been able to interpret properly this divi- 
sion on account of vague conceptions of division in vegetative cells. Follow- 
ing Haecker’s scheme his formule are as follows. For the vegetative 
division : 
a c d e Ri etc. 
a b c d é : 7 etc. 
In the heterotype division the chromosomes are united in pairs with the 
following formula: 
b c+d e+ f etc. 
Their division leads to the formation of daughter nuclei with the seg- 
ments 
a+ és ec +d e+ f etc. 
ee 
£8 t+ @ e+ f etc. 
The second pies in aise pollen mother cells leads to the separation of 
the halves of the segmen 
a ¢ @ etc. 
SON BAST Oe ae a 
b ad get etc. 
. Whether the grouping of the segments is accidental or determined must 
remain unanswered. At any rate, the chromosomes of the nuclei resulting 
* Ber. der deutsch. Bot. Gesells, 16 327-34. 1898. 
