121 



gave the 2x number of chromosomes repeatedly as 36. 

 In the endosperm the exact number was not made out 

 with absolute exactness. In one mitosis, however, 48 

 chromosomes could clearly be distinguished of which 

 number at least 30 were nicely arranged in pairs. The 

 figure 54 was awaited, but rather often, as Tischler 

 (1916) recently has pointed out, a lower number is found. 



Thèse figures make it highly probable that x = 18 and 

 2x = 36. 



The female flowers of Aucuba remain open for a rather 

 long time. The embryosac is usually not ready untill 

 about 4 weeks after the opening of the flowers. When 

 the flowers open, the megaspores are either not yet or 

 just formed. The divisions in the embryosac take place 

 at long intervais. 



Already Warming (1878) described the ovulum of 

 Aucuba japonica as provided with a single, thick integu- 

 ment, surrounding a rather strongly developed nucellus. 

 Figs 1—2 show thèse features better than any description. 

 The next two figs hâve been drawn to point out another 

 point of interest '). In fig. 3 is the single embryosac 

 mother cell covered with a tapetum only of some few 

 cellayers thickness. This tapetum increases rapidly in ail 

 dimensions and has, on fig. 4, already buried the embryo- 

 sac mother cell at the bottom of the nucellus, where the 

 gametophyte will remain during the following development. 

 As a mighty cap on the embryosac the tapetum continues 

 its growth till late in endospermformation. The ripe 

 embryosac occupies only about V4 of the nucellus and 

 seems to get a certain amount of nutrition from there 

 for the ripening of the embryo, the cells of the nucellus 

 being largely filled up with starch grains about that period. 

 In other, till now studied members of Cornaceae, belon- 



1) Figs 3-12 200 X. 



