304 BOTANICAL GAZETTE [APRIL 
hours is necessary for the growth of the pollen tube and the fusion 
of the nuclei. 
No evidence of prochromosomes was found in the pollen mother 
cells. 
The formation of the gemini and the reduction division appar- 
ently follow the hétérohoméotypique scheme of GREGOIRE; but 
no split in the chromosomes is evident in the anaphase of the first 
division. 
The reduced chromosome number is 8. 
In the anaphase of the reduction division of the microspore 
mother cells the chromosomes of the short-styled form have a 
diameter nearly twice as great as do those of the long-styled form. 
At this stage the chromosomes of the short-styled form are 
arranged six in the peripheral ring and two in the middle; while 
those of the long-styled form are arranged seven in the periphery 
and one in the middle. 
In the long-styled form the ‘“‘central’’ chromosome of one of the 
daughter cells of the first division appears to be larger than its 
synaptic mate, 
Interkinesis is characterized by a partial reconstruction of the 
nuclei, a nucleolus appears, and the chromosomes become somewhat 
vacuolate but never lose their identity. 
A difference in size of the pollen mother cells of the two forms, 
corresponding to the difference in the size of the pollen grains, is 
evident at diakinesis. This difference apparently arises through 
the greater growth of the pollen mother cells of the short-styled 
form up to this stage, for no difference in the size of the somatic 
cells can be found. 
At the separation of the cells of the tetrad a thick wall, appar- 
ently homogeneous and extremely resistant to stains, is formed 
surrounding the pollen mother cells and separating the pollen grains. 
As the tapetal cells degenerate, they show free nuclear division 
which is to some extent at least amitotic. 
Usually only one megaspore mother cell is formed in an ovule, 
but one ovule was found which showed two well-developed mega- 
spore mother cells. These had apparently arisen by the longi- 
tudinal division of a single cell. 
