92 BOTANICAL GAZETTE 
no cellulose wall is formed. The second division follow” 
‘promptly, cutting off a similar cell (fig. 2), and a third gies” 
rise to the generative cell and the tube nucleus (fg. 3). Te” 
spindles of all the divisions are much broader at the prothallit _ 
than at the opposite end, as figured by Coulter and Chamberlat 
— (1901) for Pinus, and the chromosomes are very large in pi 
tion to the spindle (fig. 3). Not infrequently this spindled | 
the third division was strongly inclined (fig. 6), and in 
. oe the generative cell may be placed in a distinctly exceat 
a otis 
The prothallial cells do not Ecoaiptly degenerate as im 
ee, but the second, and sometimes the first also, ben 
oandthe Cycads. Both nuclei organize a coarse ! 
nucleolus, and i increasing in size become as comsp! 
: occupy, half the diameter of the pollen grain 
the development of the two prothallial cells has 
at this int their paths as a rule diverge. 
ae > Secon: loses its individuality and becomes 
| from that of the tube (or wall) cell, and its 
ae ition and lies free in the general § 
: it 
ion and lay side by side (fi 
t of = excentric pee of 
‘tain (1901 vies both  peothattat nucle’ 
but this condition i is shortly followed | by 
