ASH 



59 



lower part of the flattened green fruit. The upper portion of the 

 latter is thin and flat, and has a slight spiral twist. The remains 

 of the style may be found springing from the slight indentation at 

 the free end. 



The fruits ultimately turn brown and dry. They remain 

 hanging for some time on the tree, but gradually become detached 

 and flutter down. The 

 thin wing formed by the 

 upper part of the fruit 

 offers a considerable sur- 

 face to the wind, and the 

 twist which this exhibits 

 further retards the fall 

 and increases the chance 

 of the fruit being carried 

 to some distance from the 

 parent before it reaches 

 the ground. Since only 

 one seed is developed in 

 the fruit there is no need 

 for the latter to open, the 

 wall of the fruit remaining 

 to protect the seed until 

 germination. The seed 

 contains a considerable 

 store of food material to 

 enable the young plant 

 to start its growth, and 

 seedlings can usually be 



found in the neighbour- FIG. 15. The Oak. A, Shoot in early summer, showing 

 hood of the tree though the folia e and the male and ^ emale inflorescences ; 



the conditions rarely 

 allow of their growing on 

 into mature plants. 



It may be added that 

 with the help of a sharp 

 knife and a pocket lens many of the features in the mode of growth 

 of a woody plant can be made out on twigs and branches of various 



B, male or staminate flower ; C, stamens ; D, pis- 

 tillate flower ; E, stalk of the inflorescence bearing 

 the fruits (acorns) ; F, the cup surrounding the 

 base of the fruit ; G, seed removed from the fruit 

 and cut across ; H, seed cut lengthwise. (From 

 Strasburger's Lehrbuch der Botam'k.) 



