428 



A TEXT-BOOK OF BOTANY. 



sclerenchymatous cells or stone cells, (3) a pigment layer, (4, 5) 

 one or two rows of parenchymatous cells, (6) a row of more or 

 less obliterated parenchyma cells. 



The EPIDERMAL CELLS vary considerably in different species 



H M 



Ji 



Fig. 250. A. — Longitudinal section through anatropous seed of linum: R, raphe; SC, 

 seed-coat; M, hilum; H, micropyle; EN. endosperm; C. cotyledon; HY, hypocotyl. B. — 

 Longitudinal section through stramonium seed: SC, seed-coat; H, micropyle; M, hilum; 

 EN, endosperm; E, curved embryo. C. — Transverse section through endosperm of nux 

 vomica showing thick-walled parenchyma, the cells containing oil and protoplasm. D. — • 

 Transverse section through endosperm of seed of Ricinus communis, one cell filled with 

 aleurone grains, each with a crystalloid and globoid, and another in which the aleurone 

 grains have been dissolved, the cytoplasm and nucleus remaining. 



both as regards the form of the cells and the composition of the 

 walls (Fig. 136). The cells may be more or less isodiametric in 

 cross-section, as in cardamom (see Vol, II) ; elliptical, as in almond 

 (Fig. 136, D) ; palisade-like, as in Abrus precatorius, or more or 



