INDEX AND GLOSSARY 



499 



which does not greatly exceed their 

 breadth and which have soft non-ligni- 

 fied walls, 60 : ground-parenchyma, 413, 

 415 



Pail'etal (paries, a wall), applied to the 

 layer of coslomic epithelium lining the 

 body-wall, 274 



Parthenogenesis (;rap0eVos, a virgin : 



yeVeo-t?, origin), development from an 

 unfertilized ovum or other female gamete, 

 200 

 Parthenogenet'ic ova, characteristics of, 



Pasteur, Louis, researches on yeast, 76 



Pasteur's solution, composition of, 76 



Pectoral Arch and Fin, 378 



Pedal (pes, the foot) ganglion, Mussel, 

 362 



Pedicellaria, 308 



Pelvic Arch and Fin, 379 



PENICILL'IUM (penicillum, a painter's 

 brush, from the form of the fully-deve- 

 loped aerial hyphse) : Figure, 186 : oc- 

 currence and general characters, 184 ; 

 mode of growth, 185 : microscopic 

 structure, 185: formation and germina- 

 tion of spores, 189: sexual reproduction, 

 190: nutrition, 190: vitality of spores, 

 191 



Pepsin (n-eVro), to digest), the proteolytic 

 or pepsonizing ferment of the gastric 

 juice, 12, 80 



Peptones, 12 



Perianth (wept, around : avQos, a flower), 



the proximal infertile leaves of a flower, 



468. 471 



Pericardial Sinus, Crayfish, 337 

 Pericardium (wept', around: KapSta, heart), 



Mussel 355 : Dogfish, 372 

 Pericycle (Trept, around : KV/cAos, a circle), 



418, 463 

 Perisperm (irepi, around : <T7repju.a, seed), 



nutrient tissue developed in the nucellus 



of the seed, 476 

 Peristom'e (n-epi, around : erro/aa, the 



mouth), Vorticelia, 128 

 Peristomlum (rrept, around : OTO/UIOV, a 



little mouth), the mouth-bearing segment 



of worms, 268 

 Peritone'um (n-eptToi/aioi'^ the membrane 



covering the viscera, 372 

 Pet'alS (TreVoAov, a leaf), the inner or dis- 

 tal perianth leaves in the flower of 



Angiosperms, 464 

 Phar'ynx (<f>apvy, the throat) : Poly- 



gordius, 277 : Dogfish, 381 

 Phloem (4>Aoi6?, bark or bast), the outer 



portion of a vascular bundle, 417 

 Phyla (<i)Aoi/. a tribe) of the animal king- 

 dom, 304 : of the vegetable kingdom, 



432 

 Phyll'ula (diminutive of <J>vAAoj/, a leaf), 



the stage in the embryo of vascular 



plants at which the first leaf and root 



have appeared, 360 : contrasted with 

 gastrula, 428 



PhylOg'eny (</>{)Aov, a race : yeVeo-is, 

 origin), the development of the race, 147 



Physiol'Ogy (4>vcris, the nature or property 

 of a thing : \6yos, a discussion), the de- 

 partment of biology which treats of 

 function, 9 et seq. 



Pigment-spot, Euglena, 47 



Pileus (/z^7, a cap\ Agaricus, 191 



Pinnule (dim. oi pinna, a feather), of leaf, 

 420 



Pistil (pistillum, a pestle, from pinso, to 

 pound.) See Gynoecium. 



Pith. See Medulla. 



Placoid scale, 369 



Plan'ula (diminutive of TrAayos, a wander- 

 ing about), the mouthless diploblastic 

 larva of a hydroid, 246 



Plant, definition of, 179 



Plants, classification of, 434 



Plas'ma (TrAa<r/u.a, anything moulded), of 

 blood, 56 



Plasmo'dium(TrA<i<r/u,a, anything moulded), 

 52-55 : comparison of with zygote, 54 



Plastic (TrAao-Tt/cos, formed by moulding) 

 products, products of katabolism which 

 remain an in tegral part of the organism, 33 



Pleopod, 321 



PleUTObranchia (n-Aevpov, side : /3payx*, 

 gills), 337 



Pleuron (n-Aevpoi', side), 320 



PodObranchia (TTOVS foot, 0payx ta giH), 335 



Pod'omere (TTOV'S, a foot : |u.epo, a part), a 

 limb segment, 321 



Polar cells, formation of, 259 



Pollen grain (pollen, fine flour), a name 

 given to the microspore (q.v.) of Phanero- 

 grams. 



Pollen-sac, a name given to the microspo- 

 rangium (q.v.) of Phanerogams. 



Pollen-tube, 45 8, 475 



Pollina'tion, 4=8, 475 



POLYGrORD'IUS (iroAvs, many : TopStos, 

 King of Phrygia, inventor of the Gordian 

 knot) : Figures, 269, 271, 282, 284, 291, 

 293, 297, 300 : occurrence and general 

 characters, 268 : metameric segmenta- 

 tion, 270 : mode of feeding, 270: enteric 

 canal, 270, 277 : cell-layers, 273 : 

 ccelome, 270: distribution of food, 278: 

 blood-system, 279 : nephridia, 281 : 

 nervous system, 283 : differentiation of 

 definite organs and tissues, 288: repro- 

 duction, 290 : development and meta- 

 morphosis, 292 



Polymorphism (TroAv's, many : M0p<fy, 

 form), existing under many forms, 249 



Pol'yplast(7roAus, manyiTrAao-Tos, formed, 

 modelled), the multicellular stage of the 

 embryo before the differentiation of cell- 

 layers or organs : Hydroids, 246 : Star- 

 fish, 316 : Moss, 405 : Fern, 427 



PORPITA(7r6pTrrj, a brooch), 249: Figure, 251 



