148 BOTANICAL GAZETTE [SEPTEMBER 
dehydrated by being passed through various grades of alcohol. 
Bergamot oil was used to precede the infiltration of paraffin 
Microtome sections from 3.6 u to 6 mu thick were used. 
THE POLLEN MOTHER CELLS OF GLADIOLUS.’ 
Gladiolus affords very exceptional material for the study of 
spindle formation on account of the large size of its anthers 
pollen mother cells, and nuclei. The cytoplasm in the resting 
pollen mother cell appears in the form of a clear uniform reti- 
culum, with numerous small spherical bodies scattered irregularly 
through it. The nucleus is very large, containing a vacuolated 
nucleolus, and the chromatin in a very characteristic spirem 
As division approaches, the cytoplasm undergoes a remarkable 
differentiation in identically the same manner that occurs at this 
stage in the corresponding mother cells of Cobaea. While the 
chromosomes are being formed, there gradually accumulates 2 © 
complete and sharply differentiated zone of granular substance 
about the nucleus. In nearly every respect this zone resembles 
the perikaryoplasm so characteristic of Cobaea. It accumulates 
in the same manner, has the same structure, and stains in the | 
same fashion. In fact, the only difference that could be detected / 
was in the size of the granules of which the zone is com 
In Gladiolus these granules are very fine, while those in Cobaea J 
are comparatively coarse. We shall therefore continue to use = 
term perikaryoplasm in the following description. 
By the time the chromatin thread breaks up and assumes 
has 
form of curved rod-shaped chromosomes, the perikaryoplas™ | 
reached its maximum development. In many cas® -— 
ere scar 
observed that the small black spherical bodies which w 
tered irregularly through the cytoplasm had arranged the can 
in the form of a ring at the outer margin of the perikary°P me 
But this peculiarity is not as constant or as striking as it 
Cobaea. ee 
At this early stage in Cobaea it was observed that t 
membrane breaks down, but in Gladiolus this does 9° 
: prid & 
*One of the common cultivated garden forms, probably of the hy 
avensis (Hort.). ies 
# 
t hap 
