12 THE OAK 



ripening of the former. At the more pointed free end 

 of the acorn is a queer little knob, which is hard and 

 dry, and represents the mummified remains of what was 

 the stigma of the flower, and which lost its importance 

 several months previously, after receiving the pollen. 



The outer hard coat of the acorn is a tough, leather- 

 brown, polished skin, with fine longitudinal lines on it, 

 and it forms the outer portion of the true covering of 

 the fruit, called the pericarp (fig. 2, p). On removing it 

 we find a thin, papery membrane inside, adhering partly 

 to the above coat and partly to the seed inside. This 

 thin, shrivelled, papery membrane is the inner part of 

 the pericarp, and the details of structure to be found 

 in these layers may be passed over for the present with 

 the remark that they are no longer living structures, 

 but exist simply as protective coverings for the seed 

 inside. 



The centre of the acorn is occupied more or less 

 entirely by a hard brown body the seed which usually 

 rattles about loosely on shaking the ripe fruit, but 

 which was previously attached definitely at the broad 

 end. A similar series of changes to those which brought 

 about the separation of the acorn from the cup 

 namely, the shrivelling up of the tiny connecting 

 cords, &c. also caused the separation of the seed from 

 the pericarp, and we may regard the former as a dis- 

 tinct body. 



Its shape is nearly the same as that of the acorn in 

 which it looselv fits, and it is usually closely covered with 



