No. 472] 



wall, the second not so cut off, while a third cell w li 

 primary spermatogenous cell divides into the stalk 



two protliallial cells, a stalk cell, a body cell, an. I 

 Land ( : 04, p. N ) remarks that it is hardly to he r\\ 

 protliallial cells will be present in one species and 

 in another of the same genus. The question, liou* 



set aside only after further examination of the s; 



Miss Ferguson (:01, PI. 12, Fig. G) fignnvs j>. 

 Pinus strobvs with two prothallial cells, and also 

 thallial cell (PI. 12, Fig. 8), and in the latter c ase 

 one cell shown as the second prothallial cell. Of n 

 the supposition that the same number of cells i> al 

 in this species, and that in the pollen grain shown 

 the first cell formed had disappeared. The (pie 

 arises, however, whether this may not be a real vai 

 prothallial cell shown, be the only one formed it- 

 carpus. The two prothallial (vll> do not [)ronipl 

 but persist as cells, and the second, and sonu'tiuie 



only paralleled among the Cycads and in (iinkgf 

 enlarge and become as conspienons as the generative 



