204 INDEX. 



Riccia, Sporogonium of, 146. 



Ricinus, Cambium of, 53, 58. 



Root-hairs, 9, 16, 32, 35 ; Osmotic phenomena in, 190. 



Root-])ressure, 71, 175, 176. 



Rosettc'-stages, see Mitosis. 



Rotation, of cytoplasm, 15, 95 ; movements caused by cUia, 97. 



Safkanin, as a nuclear stain, 15, 102, 104. 



.Salts, Absorption of, 9, 32, 172, 173, 190 ; essential to green plants, 157 



Salvinia, see Heterosporous ferns. 



Sambuous, Cork in stem of, 38. 



Sansevieria, Sclerenchyma in leaf of, 41. 



Sap, Raw, 170, 172, 176, 177; Upward conduction of, 71, 174, 175, 17fi, 



177 ; Elaboration of, 172, 176, 177. 

 .SaUcylic acid, Occurrence of, in plants, 171. 

 Schizogenous, origin of ducts, 83. 

 Schulze's solution, as reagent for cellulose and starch, 17, 92 ; as reagent 



for stem-sections, 74. 

 Sclerenchyma, 40, 41, 65. 



Secondary thickening, of stems, 52 ; of cell-wall, 44, 45. 

 Secretion, 159, 160, 165. 

 SelagineUa, see Heterosporous ferns. 

 Selective capacity, 9, 32, 172, 191. 

 Sieve-plate, 60. 



Sieve-tube, Origin and structure of, 60, 62. 

 SUica, in walls of Diatoms, 99 ; as occasional constituent of saji, 157, 170, 



171. 

 Siphoneie, see Vaucheria. 

 Sodium, occurrence in plants, 157, 170. 

 Soredia, 88. 

 Sparganitim, prothaUial cell of microspore, 121, 155 ; divisions of antipodal 



cells, 155. 

 Spectrum, absorption of chlorophyll, 166. 

 Sphaerella, 95, et seq. ; Structure of, 97 ; Pyrenoids in, 97 ; Reproduction 



in, 98. 

 Spheroids, 84, 87, 176. 

 Spireme, see Mitosis, 

 Spirogyra, Structure of, 90 ; Pyrenoids in, 90, 91, 92 ; Reproduction in, 



93, 147 ; Amitosis in, 93 ; Chlorophyll band of, 90 ; Plasmolysis in, 



91. 

 Spongioplasm, 10. 

 Spongy parenchyma, 28, 36. 

 Spores, of Homosporous ferns, 118, 119, 140 ; of Heterosporous ferns, 118, 



119, 144 ; of fungi, 89, 146, 147. 

 Sporophyte, of Angiosperms, 117, 128 ; of Gymnosperms, 137, 139 ; of 



• ferns, 143, 145. 

 Stains, Nuclear, 102, 104 ; Plasmatic, 17, 22, 92 ; for guard-cells, 31 ; 



for wood, 71 ; for sieve-plates, 62 ; for sclerenchvma, 41. 



