166 SEEDS 



The student should observe 



(a) The angular shape of the seed, 



(b) The dry mucilage, which cements them together, 



(c) The taste of the kernel and seed-coats. 



FIG. 92. Quince seed. A, the seeds cemented together by muci- 

 lage, natural size. B, a single seed, natural size. C, the same, 

 softened in water and magnified 3 diam. D, transverse 

 section of B. E, portion of the same, magnified 190 diam. ; 

 a-, the epidermis, in which the mucilage is secreted ; v, endo- 

 sperm. (Berg.) 



Constituents. The principal constituent of quince seeds is the 

 mucilage, of which they are said to yield as much as 20 per cent. 

 It is contained in the cells of the outer epidermis of the seed-coat, 

 and swells and dissolves when the seeds are soaked in water. The 

 seeds also contain about 15 per cent, of fixed oil and probably a 

 small proportion of amygdalin and of emulsin since they evolve an 





