igo 



A TEXT-BOOK OF BOTAXY. 



A B 



Fig. 1 10 A few illustrations showing the practical value of the study of calcium 

 oxalate: A. digitalis, without any calcium oxalate; B. hyoscyamus in which monocHnic 

 prisms predominate; C. belladonna, characterized chiefly by sphenoidal micro-crystals as 

 well as occasional prisms; D, stramonium, having rosette aggregates in addition to prisms 

 Which are found in the petioles and stems and sphenoidal micro-crystals, which are abundant 

 m the root.— a. upper epidermis; b, lower epidermis; c, non-glandular hairs (which in stra- 

 monium art tuberculate); d, glandular hairs; e. calcium oxalate crystals; f. fragments of 

 xylem showing tracheae with bordered pores (s), reticulate markings (r). simple pores (p). 

 spiral thickening (1). and wood fibers (w); g. bast fibers, which, together with wood fibers, 

 are wanting in digitalis. 



