390 INDEX-GLOSSARY. 



Papillose Covered with small papilla?, 286. 



Paranucleus (micronucleus) A small reproductive nuclear structure by the 

 side of the main nucleus, 13/16, 72. 



Parasite An organism living in, or upon, another organism and deriving 

 nourishment from it, 17, 313 ; endoparasite, 17, 28, 39, 47, 313 ; 

 intracellular p., 18. 



Parenchyma (Trapevxyp-", the spongyj-oubstance of'the lungs) Tissue com- 

 posed of cells which are fairly equal in their different dimensions, 41. 



Parthenogenesis (irapdevos, a maiden ; yevvaw, I produce) Development of 

 an ovum without fertilisation, 39, 74. 



Pearls, 113. 



Pearly layer, 110, 125. 



Pecten (pecten, a comb), in the Pigeon A plaited vascular fold projecting 

 into the vitreous humour of the eye, 256. 



Peduncle (pedunculus, a little stalk) One of the bands of fibres uniting 

 the cerebellum with the rest of the brain, 253, 302. 



Pelvis = (1) The hip-girdle + the sacrum. See Hip-girdle. (2) The dilated 

 end of the ureter, within the kidney, 295. 



Penis A copulatory organ, 32, 42, 80, 131. 



Pentadactyle (irevre, five ; SUKTU\OS, a finger) With five digits, 176. 



Pepsin A proteid-digesting ferment found in the gastric juice, 194. 



Peptone A soluble form of proteid matter, 58. 



Perch, 153. 



Pericardial cavity, 195. 



Pericardium (u-eps around ; /capita, the heart) The space surrounding the 

 heart, 245, 289. 



Perichondrium (Trepl ; x"^Ps, cartilage) The fibrous membrane which 

 invests cartilage, 188. 



Perilymph (trepl lympha, water) A clear fluid surrounding the mem- 

 branous labyrinth, 219, 255, 304. 



Perineum, in the Rabbit The area between the anus and urinogenital 

 aperture, 269. 



Periosteum (^repl ; 6<rreov, a bone) The fibrous membrane investing bone, 



188. 

 Periostracum (irepi; oaTpaKov, a shell), in the Mussel and Snail The pig- 



mented horny membrane which covers the shell, 110, 125. 

 Perissodactyla (-jrepio-o-os, odd ; SCIKTV\O<:, toe), 346, 355. 

 Peristaltic action The wave-like contraction of muscle or of the muscular 



wall of a tube, 209. 



Peristome (irtpl ; cro/ma, the mouth), 13, 123. 

 Peristomium (Trepi ; o-To/za, the mouth), 55, 75. 

 Peritoneum (-ntptTovfiov, used with modern meaning ; irepi, around ; 



