5o6 



GLOSSARY 



Ploughshare -bone : (i) in Birds, the bone 

 which suppurLs the tail- quills ; (2) in the 

 Mole, a flat curvtd bone on the inner side 

 of the hand. 

 Pluteus, pi. -ei (L. for a roof made of hurdles), 

 in Brittle-Stars and Sea-Urchins, the bi- 

 lateral larva, which is provided with pairs of 

 ciliated arms, and supported by an internal 

 calcareous skeleton. 

 Pneumatic duct, in Fishes, a tube which 

 (temporarily or permanently) connects the 

 swim-bladder with the gullet. 

 Polar bodies, in the maturation of the eg:g- 

 cell (ovum), two small cells resulting" from 

 the last two cell-divisions. 

 Pollen (L. for fine flour), in flowers, the 

 tertilizing substance produced by the 

 stamens, and consisting of minute; pollen- 

 grains. 

 Pollen-tube, a delicate tube growing from a 

 pollen-grain, and effecting the fertilization 

 of the egg-cell. 

 Pollination, in flowers, transfer of pollen to 



the stigma. 

 PoUinium, pi. -ia, an agglutinated mass of 



pollen. 

 Polype, in Zoophvtcs (Co^lenterata), an in- 

 dividual animal. 

 Portal veins, veins which carry impure blood 

 to the liver (hepatic portal vein) or to the 

 kidneys (renal portal veins). 

 Post-axial, behind the axis of a limb. 

 Posterior nares, the opening or ojienings by 

 which in air-brcalhing\'ertebratesthc cavities 

 of the nose open into the mouth-cavity or 

 pharynx. 

 Pre-axial, in front of the axis of a limb. 

 Precoracoid, a skeletal element present in 



front of the coracoid in some animals. 

 Preformation, the obsolete theory that the 

 development of an animal results from simple 

 increase in size of parts already present in 

 miniature. 

 Prehensile (L. prehcnso^ I seize), grasping. 

 Premolar, one of the permanent cheek-teeth of 

 a jMammal, belonging to the front part ot 

 the series, and often preceded by a Milk 

 molar (which see). 

 Primary, inherited from remote ancestors. 

 Proboscis (the Greek name), an elongated 

 structure at the front end of certain animals, 

 e.g. the trunk of an elephant or the sucking 

 mouth-parts of a butterfly. 

 Process, a projecting part, e.g. of a bone. 

 Proccelous (Gk. prh-^ in front; koiWs., hollow), 

 applied to vertebras of which the bodies are 

 concave in front and convex behind. 

 Producteur, a French oyster-culturalist con- 

 cerned with production. 

 Production, in French oyster-culture, the col- 

 lection and rearing of spat. 

 Proglottis, pi. -ides (Gk. proglussis^ the tip of 

 the tongue), in Tape-Worms, one of the egg- 

 producing joints ot the bod>'. 



Pro-legs, in Insect-larvae, temporary sucker- 

 like legs. 



Pronation (L. pronus, prone), position of the 

 fore -arm when back of hand is directed up- 

 wards. 



Prosobranch (Gk. />w-, in front of; branchiae 

 gills), applied to Sea-snails with gill or gills 

 in front of the heart. 



Prostomium (Gk. pro-^ before; stdma, a 

 mouth), the head-lobe. 



Proteids. See Albuminoids. 



Protocercal (Gk. proWs, first; ki'rkds, tail), 

 apphed to the symmetrical unlobed tail ot 

 some fishes. 



Protoplasm (Gk. protos^ first; plas?}ia, that 

 which has been formed), the complex sub- 

 stance which makes up the living part of the 

 bodies of all organisms. 



Proventriculus {G'k. pro-, in front of; L. ven- 

 iriculus, the stomach), the first or chemical 

 stomach ot a Bird. 



Proximal, at or near the attached end. 



Psalter. See Of/iasum. 



Pseudobranch (Gk. pseudes, false; branchiuy 

 gills), a gill which has been reduced to a 

 Vestige (which see). 



Pseudopodium, pi. -ia (Gk. pscudes, false ; 

 pous, podos, a foot), in naked Animalcules, 

 one of the blunt lobes which can be pro- 

 truded by the protoplasm. 



Psychology (Gk. psyche, the mind; logds, a 

 discourse), the stud}- of mind. 



Pteryla, pi. -ae (Gk. pferbn, a plume), a 

 feather-covered tract of skin. 



Pubis, the ventral and anterior element of the 

 hip-girdle. 



Pulmonary (L. pulnio^ a lung), relating to the 

 lungs. 



Pulvillus, pi. -i (L. pulviUus, a little pillow), 

 in the feet of some Insects, an adhesive 

 end -flap. 



Pupa (L. for a doll), in Insects, a motionless 



stage in the life-history. 

 Pupil (L. pupilla, same meaning), the opening 



in the Iris (which see). 

 Pygal (Gk. pyge., the rump), related to the 



hinder part of the body. 

 Pyloric, applied to that end of the stomach 



which adjoins the intestine. See Pylorus. 

 Pylorus (Gk. pyJaoros, having charge of a 

 gate), the opening between stomach and 

 intestine. 



Quadrate bone and Quadrate cartilage, a 



bone (or cartilage) bv which the lower jaw 

 is attached to the skull in most \'ertebrates 

 except Mammals. 

 Quarter-evil. See Anthrax. 



Rachis (Gk. I'hacJiis, the backbone), the axis 

 of a feather. 



Radial, in radially symmetrical animals, relat- 

 ing to a radius. 



Radiale, a proximal element in the carpus, 

 situated on the side next the thumb. 



