2l8 



BOTANY AND PHARMACOGNOSY; 



and flaxseed (Fig. 184) ; or to non-glandular hairs which consist 

 either of cellulose, as in cotton (Fig. 166), or lignocellulose, as 

 in nux vomica (Fig. 283, B). 



The PERisPERM and endosperm (Fig. 121) consist chiefly of 

 parenchyma cells, which contain, besides protoplasm, starch, as 

 in physostigma; oil, as in strophanthus (Fig. 186); aleurone 



Fig 121. Form of embryo and distribution of endosperm in various seeds and 

 fruits. A, Ricinus seed: car, caruncle; m, micropyle; e, embryo. B, superior drupe of 

 Piper: per, pericarp: e, endosperm; p, perisperm. C, spinach fruit and D, com cockle seed 

 {Agrostemma Githago): per, pericarp; t, seed-coat; h, hilum; p, perisperm; e, endosperm 

 c, curved embryo. — A, C, D, after Harz; B, after Baillon. 



grains, as in ricinus (Fig. 122) ; glucosides, as in almond; alka- 

 loids, as in stramonium. The walls are usually thin, but may in 

 some instances be considerably thickened, as in coffee, colchicum 

 and nux vomica (Fig. 122, C). 



The embryo consists chiefly of parenchyma cells with a few 

 fibrovascular bundles; the cotyledons may be thin and leaf -like, 

 as in ricinus and nux vomica, or thick and fleshy, as in almond 



