152 



INDEX 



Root, ontogeny of primarj^ vascu- 

 lar tissues in, 132 

 primary tissue regions in, 131- 



133 

 secondary growth in, 133-134 

 study of in Banuncidus, 134-13G 

 study of in Smila^r, 136 

 Root apex, contrasted witli shoot 

 apex, 131 

 histogens in, 25-26 

 structure and gi'owth of, 25-27, 



130-131 

 study of types of, 26 

 suhterniinal nieristeni of, 25, 



130-131 

 types of, 26, 130-131 

 zones in. 26 

 Root cap, function of, 25 



methods of origin, 26 

 Root hairs, position of, 131 

 Rubber jilarit, multiple epidermis 

 of, 50-51 



SCALARIFORM elements, of 

 protoxylem, 84 



perforation, 83, 88, 89 

 Scales, ontogeny of, 54 



tyix's and structure of, 52 

 Sclereides, dcliunification of Avails 

 of, 6!) 



function of, 60-70 



material for study of, 70-71 



ontogeny of, ()8-69 



origin and use of term, 67 



protophists of. ()!) 



types of, 67-()8 



wall slructure of, 67 

 Sclereiicliymn, ci'iticiue of term, 6^ 

 Secondary growth, in roots, 133 

 134 



in stems, 106-108 



study of in roots, 136 



studv of in stems, 110-111, 113- 

 116, 119-120 



Secondary meristem, illustrated 

 by cambium, 27 

 phloem, cell types in, 94 

 sclerosis, descrijjtion of. 68-6i) 



in stem of Aristulocliia, 120 

 vascular tissues, contrasted with 



prinuiry, 86-87 

 wall, discontinuous character of, 

 10-11 

 in sieve-elements, 98 

 of primary xylem tracheae, 



84-86 

 origin and structure of, 10-11 

 study of, 11 



three-layered type of. 10 

 use of term, 10 

 xylem (see tracheid and vessel) 

 cell-arrangement in, 86 

 nuiterial for study of, 88-90 

 Secretorv cells, of resin canals, 



ii7 



Sclaginelld, vessels of, 82 

 Senrcio, study of epidermis of, 49 

 SejDtate fibers, structure of in 



VUix, 78 

 Sliepherdia, scales of, 54 

 Shoot, morphology of, 101 

 Shoot apex, central vacuolated 

 zone in. 20 

 diameter in angiosperms, 22 

 diameter in gynniospei'ins, 22 

 form of cells in, 22 

 in species with decussate phyllo- 



taxis, 21-22 

 of angiosperms, 21-25 

 of Ci/ciis rrrohitd, 20, 22 

 of I)i()o)i fdiilp. 20 

 of Giiil:(/<i hiJohii. 20 

 of gynniosperms, 20, 22, 25 

 of Zaniid, 20 

 study of angiospermous ty]ies, 



24-25 

 studv of gvmnospermous types, 

 25 



