794 



BOTANY AND PHARMACOGNOSY. 



a fixed oil and aleurone grains (Fig. 318, E). Small, nearly 

 spherical starch grains occur in the tissues of adhering fruit pulp. 

 It is occasionally adulterated with olive endocarp and seeds of 

 Metroxylon viticnsc. 



253. ALMOND. Both bitter almonds and sweet almonds 

 have characteristic, rectangular, somewhat rounded stone cells in 

 the outer epidermal layer of the seed-coat. These stone cells are 

 from 70 to 17s F- ^o"fe a^d from 65 to 100 |U, wide; the walls are 

 from 10 to 15 |Li thick and have numerous simple pores. The seed- 



FiG. 319. Alrnond meal: a, stone cells of the outer epidermis; K, brown hypodermal 

 cells; sp, spiral tracheae of the seed-coat; ep, cells of inner epidermis with brown contents; 

 E, cells of the endosperm containing numerous small aleurone grains; Ca, epidermal cells 

 of cotyledons; C, parenchyma of the cotyledons containing aleurone grains and oil. After 

 Moeller. 



coat also contains tracheae with spiral thickenings, associated with 

 which are cells containing rosette-shaped or prismatic crystals of 

 calcium oxalate that are about 7 i". in diameter. The endosperm 

 consists of a single layer of nearly cubical cells about 15 ju. in 

 diameter. The cells of the embryo contain numerous aleurone 

 grains, which are from 5 to 15 /x in diameter and consist of crys- 

 talloids, globoids and calcium oxalate (Figs. 187; 188; 302, D ; 



319)- 



Substitutes. The seeds of other plants of the Rosaceae are 

 sometimes substituted for Almond seeds. These usually have a 

 bitter and more or less disagreeable taste : the outer epidermal 

 cells in apricot and plum being elongated tangentially, while 

 those of peach are somewhat narrower and more or less conical. 



