530 



MANUAL OF BOTANY 



Paraphyses. Hair-like outgi'owthsfonned 

 among tlie sexual organs or sporangia 

 of Thallophytes, Bryophytes, and 

 Ferns, 44 



J'nrasites. Plants whicli live upon other 

 plants or animals by absorbing nntri- 

 tire materials fi-om their tissues, 482 



Paratonic action of light, 488 



Parthenogenesis. The development of a 

 ne\i' plant from a sexual cell without 

 fertilisation, 523 



Pectase, 455, 457 



Peloria. A term applied to the condition 

 when flowers which are normally ir- 

 regular in form become regular 



Pepsin, 455, 477 



Perihlem. The embryonic tissue whicli 

 gives rise to the cortex of vascular 

 plants 



Pericamhium. An old name for the peri- 

 cycle of the root 



PeiicliEetium, 107 



I'ei-idinal. A term applied to cell-walls 

 which are formed pEirallel to the sur- 

 face of the growing point 



Pericycle. The circumferential layer of 

 the stele 



Peridium, 92 



Perigynium, 108 



Perinium, 147 



Periodicity, 510 



Peripherical . A term applied to the 

 embryo when it more or less completely 

 surrounds the endosperm in the seed 



Periplasm, 79 



Pemsperm. The remains of the nucellus 

 of the ovule when it is not all absorbed 

 by the macrospore or embryo sac durin g 

 the development of the latter, 177 



Peristome, 118 



PeritliGCium, 85 



Phototaxis, 494 



Phototonus, 484 



Phragmata. Spurious dissepiments cross- 

 ing the ovary horizontally, as in Cassia 



Phycocyanine, 26 



Phycoerythrine, 36 



Phycophseine, 36 



Phycoxanthine, 36 



Phyllaries. The bracts forming the invo- 

 lucre of the CompositEe and allied ordei-s 



PhijUotaxis. The arrangement of the 

 leaves upon the stem 



Pileus, 91 



Placenta. The part of the sporophy^e on 

 which the sporangia arise 



Plasmodium. The body of a Myxoniv- 

 cete, 67, 76 



Plerome. The embryonic tissue which 

 gives rise to the stele 



Pollination, 518 



Pollinia^ The masses of pollen produced 

 in the lobes of the anthers of the 

 Orchidace^ and Asclepiadaceae 



Polliuodium, 70, 79 



Polliuoid, 50 



Polygamous, 520 



PoJiistelii. Tlie condition in which the 



vascular tissue of the axis is arranged 

 in several steles, each containing more 

 than one vascular bundle 



Pr(£floration. The arrangement of the 

 leaves in the flower-bud 



Prefoliation. The arrangement of the 

 foliage leaves in the bud 



Prepotency, 521 



Primordial cells. Cells with no cell-wall 



Primordial utricle. The part of the 

 protoplasm of a cell which lines the 

 cell-wall 



Procambium. The embryonic tissue that 

 develops into the vascular bundles 



Procarpium. The female organ of the 

 Ehodophyeese and the Ascomycetes 



Pro-embryo of Chara, 65 



Pro-mycelium, 66, 78 



Protandry, 520 



Proteids, classification of, 445 



Proterogyuy, 520 



Prothallium, 125 



Protobasidium, 88 



Prolonema. The body produced from the 

 spore of a Bryophyte, on wliich the 

 gametophyte is developed vegetatively 



'Protoplasts. The separate aggregations 

 of protoplasm, each of which consti- 

 tutes the living substance of a cell, 409 



Pseudocarp. A fruit into the compo- 

 sition of which other parts than the 

 pistil enter 



Pseudopodia, 76, 507 



Pycnidia, 85 



Pyrenoids, 37 



Quincundal. A term applied to the 

 Eestivation of such flowers as have 

 flve leaves in a whorl, arranged so that 

 two are overlapped on both sides by 

 their neighbours, two are not over- 

 lapped at all, anil the fifth is overlapped 

 on one sidp only 



Paces, 3 



Eamenta. 129 



Raphe. The part of the funiculus which 

 is adherent to the side of an aiiatro- 

 pous or amphitropous ovule 



Receptacle. The dilated apex of a 

 peduncle on which sevei'al flowers are 

 borne, as in a capitulum. Sometimes 

 applied to the axisof tlie flower within 

 or above the calyx 



Pectipetality, 478 " 



Pejuvenescence. A process in which the 

 protoplasm of a cell withdi-aws from 

 the cell-wall, rounds itself off in the 

 cavity, and secretes a new cell-wall 

 for itself. It is one of the processes 

 of the formation of new cells 



Rennet, 456 



Peplum. Tlie spurious longitudinal dis- 

 sepiment of the siliqua and silicula. 

 It is foi-med by an outgi-owth from the 

 two placentas, and not by the edges of 

 the carpeUai-y leaves, 274 



