332 



BOTANICAL GAZETTE 



[OCTOBER 



(13), IP 



the time the mother cells are dividing or a little 

 iclei of some of the tapetal cells divide without the 

 cell walls, and tapetal cells with one, two, or three 

 nd, being much like those described for Hamamelis 

 V purpurea (19), and Ulmus (15) in this respect. 



1 



3 



7 



8 



9 



10 



II 



12 



4 



Figs, i 12.— Fig. 1, cross-section of the anther showing archesporium; fig- 



- -o- -) <-i"ar>-Bc*,i.niii w me aniner snowing arcnesponum, "g- -> 

 primary sporogenous and primary parietal cells in longitudinal section; fig. 3, pnm ar >" 

 sporogenous cell and plate of parietal cells in cross-section; fig. 4, two daughter cells 

 of primary sporogenous cell in cross-section; fig. 5, cross-section of spore mother cells; 

 11 ' ngltudinal section of spore mother cells; fig. 7, first division of spore mother 

 cell; fig. 8, two-celled stage of spore mother cell; fig. g, second division of spore 



mother cell; fig. 10, tetrad, early stage; fig. n, later stage of tetrad; fig. 12, mature 

 pollen gram . 



