284 



LUSSOJVS WITH PLANTS 



LIV. REINFORCED FRUITS, CONCLUDED 



334. Acorns are shown, about natural size, in 

 Figs. 282-290. The nut itself is a pericarp contain- 



inga single seed. The ovary 

 is really 6-ovuled, but only 

 one ovule ripens into a seed. 

 About the base of the peri- 

 carp is a scaly structure which 

 is interpreted to be an in- 

 volucre. The leaf- like struc- 

 ture of this cup (or cupule, 

 whence the name of the oak 

 and chestnut family, the Cu- 

 puliferse) is apparent in some 

 of the oaks like the bur 

 oak (Fig. 283), in which the 

 scales are much developed ; 

 demonstrated by the 2 -leaved 

 and filbert, which are related 



Pig. 290. 



An English oak, often 

 planted in this country. 



and it is especially 

 husks of the hazel 

 plants. 



334a. The pupil should determine what time elapses from bloom- 

 ing-time to the ripening of the acorn. This can be discovered by 

 observing the ages of the wood (or twigs) upon which the flowers and 

 the acorns are borne. He should compare, in this respect, the 

 white oak tribes (including the live oak, chestnut oak and bur oak) 

 and the black oak tribes (including the scarlet, red and black oak). 

 The same oaks should be contrasted as to the position of the 



