358 



Tin: AMKinr.W \ ATI ' h'A LIST [Vol. XLI 



the second protluilluil cell in b figure 2, the nuclei are still in the 

 spireme condition. Occasionally anticlinal divisions occur in the 

 generative cell as in the prothalhal rudiments. One such case is 

 re{)resented in c figure 2, which is an obvious and clear mitosis. 

 I sually however in P. 'polystachya such divisions of the generative 

 cell do not occur, although they are exceedingly common in some 

 ol the other species which we have had the opportunity of study- 

 ing. At about this time the prothallial cells lose their walls; and 

 their nuclei, floating freely in the cavity of the inicros{)ore, are no 



longer (mkIom-iI liy ( ytoplasmic liodit^s. The nuclei, however, 

 persist inilflinitfly and j)a^s out as a swarm into the pollen tube. 



spore at this >tauc, tlic ivsidiml or tiilx" mich-us can l)(> distinguished 



cell, or the central cell dcrivcil from it in ca-c it has undergone 



