INDEX 



151 



Procaiubium, characteristics of, 

 86-87 

 origin and development of, 23, 



104-106 

 origin of primary 2)hloem from, 



105-106, 132 

 origin of primary xylem from, 



84-86, 105-106, 132 

 produces primary vascular sys- 

 tem, 27 

 Prodesmogen, use of term, 105 

 Progressive differentiation, from 

 meristems, 20 

 of primar}^ stem-tissues, 102 

 Protoderm (see also dermatogen), 

 origin of epidermis from, 

 45-46 

 origin of tridiomes from, 51 

 Protophloem, in carrot, 132 

 Protoidasmic plant anatomy, 3!) 

 Protoplast, 1-6 

 Protostele, general structure of, 



103 

 Protoxylem, traclieary elements 

 of, 84-85 

 use of term, 84 

 Pro vascular meristem (see also 

 procambium), produces 



primary vascular system, 

 27 

 tissue, origin and development 

 of, 23, 104-106 

 origin of primary i)hloem 



from, 105-106, 132 

 origin of primary xylem 

 from, 84-86, 105-io6, i32 

 Psilotales, sporophyte of, 101 

 Pteridiuui, primary xylem tra- 

 cheae of, 88 

 Pi/rKs, brachysclereides of, 70 

 stone-cells of, 70 



QUEECrS, libriform tibers of, 78 

 tracheids of, 89 



Quercus, vessel-elements of, 80-90 



RANUNCULUS, storage paren- 

 chyma of, 59 

 study of root of, 134-136 

 Raphides, form and structure of, 5 

 in Lemna, 5 

 in Tradescantia, 5 

 Ray initials, 27, 106 

 Rays, origin of from cambium, 27, 

 106 

 origin of in roots, 133-134 

 Regeneration, with reference to 



meristems, 21 

 Regressive differentiation, and 

 concept of meristematic 

 tissue, 21 

 and origin of phellogen, 107 

 and "i^ermanent" tissues, 32 

 of collenchyma, 62 

 of epidermis, 46 

 of parenchyma, 58-59 

 Reserve food, examples of, 4 

 Resin canals, origin and structure 



in pine, 117 

 Reticulate elements, of metaxylem, 



85 

 Rib meristem, concept of, 24 

 in roots, 26 

 origin of cortex and ])ith from, 



24 

 structure and growth of, 24 

 Rims of Sanio (see Crassulae), 



13, 89 

 Jxuhiiiia, ontogeny of vessels in, 

 83-84 

 study of cambium of, 28 

 study of phloem of, 99 

 Root, branching of, 132-133 

 cortex of, 131 

 endodermis of, 131 

 epidermis of, 131 

 general features of, 130 

 material for study of, 134-136 



