BITTER ALMOND 



295 



Description. Anatropous, ovate or oblong-lanceolate, flattened, 

 more rounded on one margin, summit acute or beaked, chalazal 

 end rounded or obliquely truncate, 20 to 30mm. in length, 11 to 17 

 mm. in breadth, 7 to 9 mm. in thickness; externally light brown, 

 with numerous parallel veins extending from the chalaza to the 

 micropyle, outer walls of epidermal cells modified to distinct papillae, 

 seed-coat thin, membranaceous, easily removed on soaking the seed 

 in water, the raphe extending on the more rounded edge as a more or 

 less distinct ridge from the hilum to or near the chalaza; fracture 

 short; without reserve layers, embryo straight, whitish, hypocotyl 

 conical, 2 to 3 mm. in length, cotyledons plano-convex, sometimes 



FIG. 131. Drupe-like fruit of almond (Prunus Amygdalus): A, whole fruit with 

 distinct suture; B, longitudinal section showing fibrous sarcocarp, and thin- 

 shelled endocarp ; C, D, E, sections of the seed; c, cotyledons; w, hypocotyl; 

 v, epicotyl or plumule. After Focke. 



slightly unequal, plumule 1 mm. in length; odorless, except on treat- 

 ment with water, when an odor of hydrocyanic acid is emitted, or of 

 benzaldehyde when the seeds have been kept for some time; taste 

 bitter. 



Inner Structure. See Figs. 132 and 133. 



Constituents. Fixed oil 45 per cent; proteins 25 to 30 per cent; 

 a glucoside, amygdalin, 1 to 3 per cent; and a ferment, emulsin, 

 which acts upon amygdalin, decomposing it into a volatile oil (ben- 

 zaldehyde or oil of bitter almond) and hydrocyanic acid. In addi- 

 tion to the protein emulsin, there is another casein-like protein present, 

 amandin, both of which act as emulsifying agents in the preparation 

 of emulsion of almonds. 



Amygdalin, or a similar principle, is found in the young shoots 

 and flower-buds, as well as seeds, of apricot, peach, plum, cherry 

 and cherry laurel. (See Wild Black-cherry Bark.) 



