122 



ging to the gênera Beiithamia (Jônson 1 880) and Davidia 

 (H orne 1909), a rather massiv nucellus has been found. 

 But they difFer from Aucuba in that respect that in both 

 gênera a many celled sporogenous tissue is developed ; in 

 Aucuba we hâve always seen, as stated above, but a 

 single archespo- 

 rial cell (figs 3-5). 

 The embryo 

 sac mother cell 

 having been défi- 

 nitely buried at 

 the base of the 

 nucellus, the ne- 

 gaspores are for- 

 med quite nor- 

 mally (fig. 5-7) 

 Almost invaria- 

 bly, of the four pjg ^ 



Fig. 2. 



Fig. 3. 



Fig. 6. 



megaspores the upper three begin to desintegrate it deserves 

 to be observed that they by no means are crushed by 

 the growing young embryosac, as is so commonly seen. 



