110 THE APPLE TEEE. 



these same pores the leaf inhales the air, and now under 

 the influence of the sun (see Chemistry, pp. 97, 181, 237) 

 the sap is converted into a thin mucilage which contains all 

 the elements of vegetable growth. The sap then descends * 

 and spreads through the tree, especially along the inner sur- 

 face of the bark, supplying every want of the young layer of 

 wood, of the leaf and the flower. 



Analysis. The Scares of the Apple Tree are com- 

 plete, having a pair of subulate (awl-shaped) stipules at the 

 base of the short petiole. The blade is ovate, serrate, and 

 beneath tomentous with a dense covering of matted hairs. 

 Its venation is pinni- veined and reticulated. 



The Inflorescence is an umbel issuing from one bud, 

 with no peduncle and therefore sessile. 



The Flowers are pedicellate, regular, 5-parted, polyan- 

 drous, perigynous, rose- white, fragrant ; the 5 sepals are so 

 united below as to form an urn-shaped fleshy tube which 

 adheres to and encloses the 5-carpelled ovary (1, 2) ; f the 5 

 petals are broadly oval, quincuncial (p. 43), inserted by their 

 short claws with the oo perigynous stamens (p. 106). The 5 

 styles are partly united. 



The fruit is a pome (3). Mark how it is crowned with 

 the persistent calyx lobes (sepals), a proof that the pome 

 consists of the enlarged calyx-tube with the enclosed ovary, 

 both gorged with pulp. Make a cross-section (2, 3) and see 

 the- 5 cells with cartilaginous walls, and the circular greenish 

 line around them in the pulp marking the boundary between 



attached to the severed end of one of its main roots. At first there was a suction 

 downward, gradually diminishing until the 10th. Thence until the 29th, an upward 

 pressure increased and attained a force equal to the weight of 88 feet of water 1 



* We can easily prove the existence of this descending current, for on making an 

 incision into the hark of a young branch, the sap will ooze from the upper and not the 

 lower lip of the cut. 



t Thus the ovary is apparently situated below the calyx, whence it is said incor- 

 rectly to be inferior, and the calyx superior. The phrase ovary adherent, or calyx 

 adherent are of the same meaning and more correct. In all the flowers heretofore 

 analyzed the calyx is free (inferior) and the ovary free (superior). 



