)30 



MANUAL OF BOTAKY 



Parajylnj^e!^. Hair-like outgrowths fomied 

 among tlie sexual organs or sporangia 

 of Thallophytes, BryopLytes, and 

 Ferns, 44 

 J'lirasites. Tlants Avhicli live upon other 

 plants or animals by absorbing nutri- 

 tive materials from their tissues, 482 

 Paratonic action of light, 488 

 l'ar(henog<'nesU. Tlie develop ment of a 

 new plant from a sexual cell without 

 fertilisation, 523 

 Pectase, 455, 457 



FeJotia. A term applied to the condition 

 when flowers which are normally ir- 

 regular in form become regular 

 Pepsin, 455, 477 



J'rribJfm. The embryonic tissue which 

 gives rise to the cortex of vascular 

 plants 

 J'ericambium. An old name for the peri- 

 cycle of the root 



Perichfetium, 107 



Periclinal. A term applied to cell-walls 

 which are formed parallel to the sur- 

 face of the growing point 



Pericijcle. The circumferential layer of 

 the stele 



Peridium, 92 



Perigynium. 108 



Periuium, 147 



Periodicity, 510 



I'eriphn-icaL A term applied to the 

 embryo when it more or less completely 

 surrounds the endosperm in the seed 



Periplasm, 79 



Perispfirm. 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 



Perithecium, 85 



Phototaxis, 494 



Phototonus, 484 



Phragmata. Spurious dissepiments cross- 

 ing the ovary horizontally, as in Cass^ia 



Phycocyanine, 26 



Phycoerythrine, 36 



PhycophJ«ine, 36 



Phycoxanthlne, 36 



Ph'iiUarifs. The Ijracts forming the invo- 

 lucre of the Conipositas and allied orders 



PliijUotnxis. The arrangement of the 

 leaves upon the stem 



Pileus, 91 



Placenta. The part of the sporophyte on 

 which the sporangia arise 



Plasmodium. The body of a Myxomy- 

 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 

 Orchidacepe and Asclepiadaceae 



Polliuodium, 70, 79 



Pollinoid, 50 



Polygamous, 520 



Polustelii. The coudition in which the 



vascular tissue of the axis is arranged 

 ill several steles, each containingmore 

 than one vascular bundle 



Pra-f oration. The arrangement of tlie 

 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 



Procar2num. The female organ of the 

 Rhodophycete and the Ascomycetes 



Pro-embryo of Chara, 65 



Pro-mycelium, 66, 78 



Protandry, 520 



Proteids, classification of, 445 



Proterogyny, 520 



Prothallium, 125 



Protobasidium, 88 



Prolonema. The body produced from the 

 spore of a Bryophj'te, on which the 

 gametophyte is developed vegetatively 



Proto2>la.^ls. The separate aggregations 

 of protoplasm, eacli 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 



Quincitncial. A tei-m applied to the 

 aestivation of such flowers as have 

 five loaves in a whorl, arranged so that 

 two ai"e overlapped on both sides by 

 their neighbours, two are not over- 

 lapped at all, and the fifth is overlapped 

 on one side only 



Races, 3 



Ramenta, 129 



Raphe. Tlie part of the funiculus which 

 is adherent to the side of an anatro- 

 pous or amphitropous ovule 



Receptacle. The dilated apex of a 

 peduncle on which several flowers are 

 boi'ne, as in a capitulum. Sometimes 

 applied to the axis of the flower within 

 or above the calyx 



Rectipetality, 478 " 



Rejuvenescence. A process in which the 

 protoplasm of a cell withdraws 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 



R/'plum. The spurious longitudinal dis- 

 sepiment of the siliqua and silicula. 

 It is formed by an outgrowth from the 

 two placentas, and not by the edges of 

 the carpellary leaves, 274 



