ri>s. 





Fig 223 -Ginkgo biloba: A, pollen grain showing the first prothallial cell, aborting; 

 second prothallial cell; and the mitosis which will form the generative cell and tube cell, 

 April 24; B, later stage, same date; C, still later stage, in the pollen chamber, July 10; 

 D the large nucleus in C has divided, July 13; E, body cell with blepharoplasts July 

 27- F two young sperms, September 1 2 ; G, two sperms just ready to be discharged from 

 th^ pollen tube, Sept. i2;A,B,C,D,E, X6oo;F, Xi44;G, X372.-After Hirase.^ss 



