126 



THE OAK 



stigma becomes the three-chambered ovary sunk in the 

 perigone. 



The pollination takes place in May-June, and ferti- 

 lisation soon afterwards ; in July the young acorns can 



FIG. 34. Female flower in section. To the left three 

 transverse sections through the young ovary ; the lower 

 one showing the three placentas, each with two ovules. 

 To the right, three longitudinal median sections through 

 the whole flower at successive periods, a, stigma ; b, 

 carpel ; 0, perianth ; d t cavity of ovary with ovules ; 

 m, the cupule. (Th. Hartlg.) 



be made out peeping from the cupules in which they had 

 hitherto been enclosed. The acorn reaches its full size 

 towards the end of September, and ripens and falls in 

 October. When ripe the acorn is, as we have seen, an 



