CONIPERALES 



91 



The third division immediately follows (Fig. 69, J), divid- 

 ing the large antheridial cell into the primary spermatogenons 



Fio. 69. — Pinus Larido, showing a series from the fonnation of the tetrads to the de- 

 velopment of the pollen tube : p, vegetative cells ; s, stalk cell ; ft, body cell ; i, tube 

 nucleus : A and B, May 3d ; C, May 10th ; D-G, May 20th ; H-J, May 25th ; K, 

 June 15th ; Z, May 1st (nearly a year after stage shown in Z") ; x 600. 



cell or generative cell, and the tuhe cell (the so-called " vege- 

 tative cell") (Fig. 69, K). Until 1891, when Belajeff^" dis- 



