INDEX 



197 



Pteridophytes, development of secondary 



wood in fossil forms of, 72. 

 Pteridosperms, 44, 104, 114, 131. 



— description of group, 114 et seq. 



— general distribution of in time, 177. 



— summary of characters of, 123. 

 Pteris attrita, 62. 



Quarries, 7, i- 

 Quercus, 83, 85. 



Race senility, 180. 

 Ranales, 103. 

 Renault, 2, 156, 187. 

 Reproductive organs, likepess between 

 those of living and fossil plants, 67, 



peculiar characters of some from the 



Palaeozoic, 74. 



simplicity of essential cells of, 52. 



Rocks, persistence of mineral constituents,, 



36. 



— fossils varying in according to the 



geological age, 37 et seq. 

 Roof of coal seam, 24, zj, 25, 14. 

 Roots, likeness of structure in living and 



fossil, 60, jj'. 



Salix, 83. 



Sambucus, 84. 



ScMzoneura, 173. 



Sclerenchyma, 56, 26, 59, 34.. 



Scott, 2, 160, 187. 



Secondary wood, development of in fossil 



members of families now lacking it, 



72. 

 Seeds, series of types from spores to seeds, 



75. 76. 52-S- 



— position on the plant, 77, 78. 



— Tertiary impressions of, 80, 81, 60. 

 Selaginella, 75, 133, 134. 7 o 



— with four spores in a sporangium, 75, 



S3- 

 Sequoia, 86. 

 Seward, 187. 

 " Shade leaves ", 171. 

 Shale, 7, 7, II, 24, 25, 36. 

 Sieve tubes, 57, 32. 

 Si^llaria, 142, 145. 



Sigillaria, cast of leaf bases, 9, ^, 144, 

 102. 



— description of, 144. 

 Silica, 17. 



Silicified wood, 17, 80, 87. 

 SoLMS Laubach, 2, 187. 

 Specimens, treatment of, 184. 

 Sphenophyllales, 44, 153. 



— description of, 153. 



— general distribution in time, 177. 

 Sphenophyllum, 44, 153, 154, 160. 



— cone of, 157, 116. 

 — fertile, 158. 



— impression of foliage, 154, 112. 



— plurifoliatttm, 153. 



— sporangia of, 158, iif. 



— stem anatomy, 155, 113, 156, 114. 



— stem in coal ball, 20. 



— wood of, 156, 114, IIS- 

 Sphenopteris, leaf impression, 11,^. 



— foliage of Pteridosperms, 115, 77. 

 Sporangium of ferns, 67, 4^. 



— of lycopods, 67, 46. 



— of pteridophytes, 75, s^, S3> S4- 

 Spores, germinating, in fossil sporangia, 



68, 47. 



— peculiar structures among palaeozoic 



examples of, 74- 



— series of types from "spores" to 



"seeds", 75, 76, ^2-5'. 



— tetrads of, 75, s^, SSi 54- 

 Sporophyll, 75, s^, S3> 54- 

 Stangeria, no. 



Stele, modifications of, 62, 36-42. 

 Stems, external similarity in living and 



fossil, 60. 

 Sternbergia, cast of, 10, 4. 



— pith cast of Cordaites, 93. 

 Stigmaria, 69, 142, 143, 144, 145. 



— rootlet of, 143, loi. 

 Stomates, 54, 23. 



— in fossil epidermis, 14, 8. 

 Stoneworts, 163. 

 Synclines, 23. 



Taxeas, 88, 90. 



— comparison of fructification with that 



of Cordaiteae, 95. 



— description of, 92. 



