GLOSSARY 



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

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

 Mole, a flat curved 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 egg- 

 cell (ovum), two small cells resulting- from 

 the last two cell-divisions. 



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

 fertilizing- 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 eg-g--cell. 

 Pollination, in flowers, transfer of pollen to 



the stigma. 

 Pollinium, pi. -ia, an agglutinated mass of 



pollen. 



Polype, in Zoophytes (Ccelenterata), 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 openings by 

 which in air-breathing Vertebratesthe 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. prehenso, I seize), grasping. 

 Premolar, one of the permanent cheek-teeth of 

 a Mammal, belonging to the front part of 

 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. prti-, in front ; koilos, hollow), 

 applied to vertebrae 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. progltissis, the tip of 

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

 producing joints of the body. 



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

 like legs. 



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

 fore-arm when back of hand is directed up- 

 wards. 



Prosobranch (Gk. prb-, in front of; branchia, 

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

 in front of the heart. 

 Prostomium (Gk. prti-, before ; stbma, a 



mouth), the head-lobe. 

 Proteids. See Albuminoids. 

 Protocercal (Gk. prottis, first; k&rkbs, tail), 

 applied to the symmetrical unlobed tail of 

 some fishes. 



Protoplasm (Gk. protbs, first; plasma, that 

 which has been formed), the complex sub- 

 stance which makes up the living part of the 

 bodies of all organisms. 



Proventriculus (Gk. prb-, in front of; L. ven- 

 triculus, the stomach), the first or chemical 

 stomach of a Bird. 



Proximal, at or near the attached end. 

 Psalter. See Omasum. 



Pseudobranch (Gk. pseudes, false; branchia, 

 gills), a gill which has been reduced to a 

 Vestige (which see). 



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

 POUS, ptidtis, a foot), in naked Animalcules, 

 one of the blunt lobes which can be pro- 

 truded by the protoplasm. 

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



discourse), the study of mind. 

 Pteryla, pi. -x (Gk. pterbn, a plume), a 



feather-covered tract of skin. 

 Pubis, the ventral and anterior element of the 



hip-girdle. 

 Pulmonary (L. pulmo, a lung), relating to the 



lungs. 



Pulvillus, pi. -i (L. pulvillus, 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. pylaortfs, having charge of a 

 gate), the opening between stomach and 

 intestine. 



Quadrate bone and Quadrate cartilage, a 

 bone (or cartilage) by which the lower jaw 

 is attached to the skull in most Vertebrates 

 except Mammals. 



Quarter-evil. See Anthrax. 



Rachis (Gk. rhachis, 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. 



