INDEX. 



607 



taining several funiculi, and each 

 funiculus capable of producing 

 several embryos, 573. 



Piperaeeee very rare in equinoctial 

 Africa, 149 ; explanation of the 

 structure of their seeds, 452 



Pittosporese, character of the order 

 and observations on its distribution 

 in Terra Australis, 13 



Pistilla and Antherse, analogy of com- 

 position in, 378 — 380 note ; proved 

 by the transformation of the one 

 into the other in cases of mon- 

 strosity, 379 note 



Pistillum of Phaenogamous plants, 

 observations on its composition, 

 269, 270 note ; hypothetical view of 

 the structure of the compound, 270 

 note; 299 note; relation of the 

 single pistillum, and of the com- 

 ponent parts of the compound to 

 calyx and corolla, and to the axis of 

 the spike, 292 ; relations of re- 

 duced pistilla, 292 — 294; complete 

 number of pistilla and stamina 

 equal to that of the divisions of 

 calyx and corolla united, 293 ; this 

 complete number equally rare in 

 both the primary divisions of Phae- 

 nogamous plants, ibid. ; Mono- 

 caryum offers the only known 

 example of reduction to a solitary 

 pistillum in the great class Liliaoese, 

 299 ; its position in tliat section of 

 Colchicum, 300 ; pistilla when of 

 equal number usually placed oppo- 

 site to the petals of Dicotyledons, 

 and to the outer series of perian- 

 thium in Monocotyledons, 300 



Placentse, relations of stigmata and, 

 553 — 563 ; necessarily double, 556 ; 

 their arrangement in the carpels, 

 of various families and plants, 557- 

 560; Cruciferae, Papaveracese, Par- 

 nassia, Iridese, 559 ; Orchidese, 

 560-562 ; manifestly double and 

 consequently marginal or submar- 

 ginal in, 560; as in Monocotyle- 

 donous plants generally opposite to 

 the three inner divisions of perian- 

 thium, ibid.; in Apostasia opposite 

 to the three outer divisions, 560-1 ; 

 in ScitamincBB, 561 ; placentae of 

 Orobanchea; double and submar-^ 

 ginal, 562 



Plantain of the banks of the Congo 

 probably of Asiatic origin, 166 



Plants, probable number of species in 

 European Herbaria [in 1814], 7; 

 proportion of Dicotyledonous and 

 Monocotyledonous in Persoon's 

 Synopsis and in Terra Australis, 8 ; 

 in the vicinity of the Congo, 101— ■ 

 106 ; how far this proportion is in- 

 fluenced by climate, 8, 102; pro- 

 portion of Acotyledonous in Terra 

 Australis, 9 ; in various parts of 

 Europe, 9 ; in the vicinity of the 

 Congo, 101 —104 ; common to equi- 

 noctial Africa, America, and Asia, 

 164; to equinoctial Africa and 

 America, but not found in India, 

 165; to equinoctial Africa and India, 

 but not found in America, 165 



Pleurothallis, spirally striated cells in, 

 615 



Plumbaginese, species in the collection 

 from Central Africa, 297 



Plurality of embryos in the seeds of 

 Coniferse, 666 — 676 ; constancy of, 

 668—572 



Poacese, a tribe of Graminese, ob- 

 servations on the tribe and on its 

 distribution in Terra Australis, 68 



Podooarpus, structure of the ovulum 

 in, 455 ; origin of the ovulum in, 

 458 ; analogy of male and female 

 organs in, 461 



Pollen, marginal production of, in the 

 antherse, ST^notej raucous tubes of, 

 observed in Cytinus, 407-8; applied 

 to the apices of the enlarged 

 ovula, 408 noUj of Cycadese, 459, 

 460 ; microscopic observations 

 on the particles contained in the, 

 463 — 486 ; mode of action of tbe 

 pollen in impregnation, 465-6, 

 476-6 ; in Asclepiadese, Periplooese, 

 and Orchideae, 476 ; motion of par- 

 ticles of pollen seen by Needbam 

 and Gleiehen, 477; observations of 

 M. Brongniart, 478-9 ; occasionally 

 in some plants continues long 

 quiescent, 574-5 ; of Tradescantia 

 Virginica, development of, 614 note. 



Pollen grains, their structure in As- 

 clepiadeae, 524 



Pollen tubes, their production and 

 course in Orchidese, 507 — 510; As- 

 clepiadese, 526-8,532; in other fami- 



