lies, 532; function of the granules of, in reference to impregnation, 533, 550-1; origin, production, growth, and function of, in Orchideæ, 537—541; in Bonatea speciosa, 537—540; mucous tubes, their growth, &c., 539, 540; traced into the aperture of the ovulum, 540; confirmed in various species, 547; traced to a definite point in the ovula of Asclepiadeæ, 550-1; their course, structure, and function in, ibid.
Polygaleæ, observations on the order and its distribution in Terra Australis, 14; on its distinction from Leguminosæ, 291-2
Pomax, undoubtedly referrible to Rubiaceæ, 36
Potalia, observations on the genus and its affinities, 133-4
Preiss, M., plants collected by, in Western Australia, 338
Primulaceæ, species found in Central Africa, 297
Proteaceæ, observations on the order and on its distribution in Terra Australis, 40; species found at Swan River, 310; few species found in the interior, 339; peculiarity in the winged seeds of, 449
Pterocarpus erinacea, the tree producing the African gum Kino, 290 and note
Radicle, position of the, in different genera of Cruciferæ, 264
Radicle, position of the, in reference to the insertion of the funiculus of less importance in Zygophylleæ than elsewhere, 287
Raffles, Sir Stamford, his journey from Bencoolen into the interior of Sumatra, 369; letter to Sir Joseph Banks on the discovery of the great flower, afterwards named Rafflesia, 370—373; letter to Mr. Marsden, with further particulars, 393-4; further specimens received from, 401
Rafflesia, account of a new genus of plants named, 367; character of the genus, 374; affinities of the genus, 383—389,401—415; compared with Asarinæ, 384-5, 389, 392, 396, 401; Passifloreæ, 386-7, 3S9; Napoleona, 387-8; Cucurbitaceæ, 388; Sterculiaceæ, 388-9; Cytinus, 396, 401; the structure and economy of its female flower, 402—410; characters of the genus, 424
Rafflesia Arnoldi, on the female flower and fruit of, 399; Dr. Arnold's account of its discovery, and description, 370—373; drawing and specimens brought to England by Dr. Horsfield, 373; description of, 374—376, 415-16; its structure, 377—383; of its column, 377; vessels wanting, ibid.; of late formation, 412, 413 note; perianthium and bracteæ, ibid.; antheræ, 377—383; possible styles and stigmata, 382, 386; impregnation, 383; insects necessary in, ibid.; discovery of female flower, 394-5; desiderata respecting, 395-6; whether parasitical on the root from which it springs, 389—392; its reticulate base, 390, 402; structure of the female flower, 403—409; internal structure of ovarium, 403—405; compared with that of Hydnora, 404; and Cytinus, 405; development of ovula, 406-7; seeds, 408; embryo, 409; its characters, 424
Rafflesia Cumingii, structure of its column and the processes surmounting it, 405 note; its character, 425; observations on its structure, 426; and nomenclature, ibid.
Rafflesia Horsfieldii, account of, 389, 390 and note; its characters, 425
Rafflesia Patma, Dr. Blume's account of, 402; its characters, 424
Rafflesiaceæ, a natural family, 410; its characters, 423
Rafflesieæ, a tribe of Rafflesiaceæ, 410; its characters, 424
Raphe, apparently external in Zygophyllum Fabago, 287; its termination affords a sure indication of the orgin of the inner membrane of the ovulum, 441; its position in relation to the placenta, 448; exceptions to the general rule, in consequence of resupination, 448; belongs to the outer membrane of the ovulum, 450
Raphides in Orchideæ, 515
