604 



INDEX. 



Naked seeds, improperly so-called, 

 defined as Akena or Caryopsis, 

 360: how distinguishable, ibid.; 

 sometimes originate in a premature 

 rupture of the ovarium, 360; iUus- 

 trated by various examples, 361-4 



Napimoea, perhaps not different from 

 Homaiium, 120 



Napoleona compared with Rafflesia, 

 387-8 



Natural orders of plants, suggestion 

 for combining them into natural 

 classes, 10, 109 ; number of, in 

 the publications of Jussieu and De 

 Candolle, 10 ; number known in the 

 Mora of Terra Australis [in 1814], 

 70 ; [in 1849], 338 



Nelson, David, plants collected by 

 him in Van Diemen's Land, in 

 Cooke's Third voyage, 6 



Neottia picta, conversion of the two 

 lateral divisions of the perianthium 

 into stamina, 501 



Nepenthes, peculiarity in the seeds of, 

 449 



Neurada prostrata, found iu central 

 Africa, 288 



Nisa referred to HomaliiisB, 120 



Nucleus, apex of the, regarded as the 

 point of impregnation of the ovu- 

 lum, 453 



Nucleus of the cell in Orchideae, 

 5 11 — 4 ; in other Monocotyledonous 

 and Dicotyledonous plants, 513 — 4 



Nuytsia floribunda, named in honour 

 of the discoverer of that part of 

 the coast of New Holland, to which 

 it is nearly limited, 308 



Nympheeacese, genera belonging to, 

 451; explanation of the structure 

 of the seed in, 451-2; arrange- 

 ment of ovula in the carpels of, 

 377 note, 555 



OlaoinK, observations on the order 

 and its affinity to Santalacese ; and 

 on the species found in the vicinity 

 of the Congo, 136 



Olax, observations on the genus and 

 its affinities, 44; on species found 

 in the vicinity of the Congo, 136 



Onagrarise, molecules in the grains of 

 pollen of various species of, 467 



Opercularia, undoubtedly referrible to 

 Eubiacese, 36 



Ophrys, monstrosity of, described and 

 figured by M. His, 501 ; impregna- 

 tion in, generally effected without 

 the aid of insects, 538 



Ophrys apifera, mucous tubes inserted 

 into the aperture of ovulum in, 

 5i0 note; eellular thread of ovulum 

 in, 547 



Ophioglossese, affinity of Triplosporite 

 to, 588 



Orange of the banks of the Congo, 

 probably of Asiatic origin, 156 



Orchidese, observations on the order 

 and on its distribution in Terra Aus- 

 tralis, 48 ; structure of the flower 

 approximated to the type of Monoco- 

 tyledons, 48 ; compared with that of 

 Scitaminese, 49 ; modifications of 

 antheree of superior importance to 

 those of labellum, 86 ; their simple 

 or acotyledonous embryo, 414-5 ; 

 observations on the organs and 

 mode of fecundation in, 487 — 543 ; 

 supplementary observations on, 545 

 ■ — 551; opinions of various writers 

 on, 490 — 8; origin of the stigmata 

 and placentaj in, 560 — 2 ; cellular 

 thread suspending tlie embryo in, 

 569 ; on the relation of the lateral 

 stamina, 499 ; believed to be placed 

 opposite to the lateral divisions of 

 the inner series of perianthium, 

 ibid. ; auriculae of the column in, 

 500 ; inner series of perianthium 

 converted into stamina in, 501 ; 

 composition of the stigma and ova- 

 rium in, 501 — 4 ; made up of three 

 component parts,"502 ; Mr. Prancis 

 Bauer's views controverted, 502-3 ; 

 functions of the different lobes of 

 stigma, 503; relative position of 

 stamina and stigmata, 504; de- 

 velopment of unimpregnated 

 ovulum, 504-5 ; conducting sur- 

 faces of the ovarium, 505-6 ; mode 

 of impregnation in, 506 — 510; 

 production and course of pollen 

 tubes, 507 — 510; distinctive cha- 

 racters of the tubes, 507 ; gene- 

 rally very numerous and forming a 

 cord dividing into six portions, 

 passing along the conducting sur- 

 faces, 508 ; tubes separating and 



