GLOSSARY. 



Perforated. Having holes, as if borec 



by a sharp instrument. 

 Pergameneous. Of the texture of parch 

 ment: a thin, tough substance, in tex 

 ture resembling parchment. 

 Pericardium. The membranous bag 

 which surrounds the heart, and th 

 arterial and venous trunks connected 

 with it. 



Pericranium. A membrane covering the 

 outside of the cranium, and corre 

 sponding to the periosteum of other 

 bones. 



Periosteum. A nervous vascular mem 

 brane immediately investing the bones 

 of animals. 

 Periostracum. The membrane anala 



gous to scarfskin which covers shell. 

 Peristaltic. The vermicular contractions 

 and motions of muscular canals, as 

 the alimentary and the circulating 

 tubes. The peristaltic motion of the 

 intestines is performed by the contrac- 

 tion of the circular and longitudinal 

 fibres composing their fleshy coats, by 

 which the chyle is driven into the ori- 

 fices of the lacteals, and the excre- 

 ments are protruded towards the anus. 

 Peritoneal. Belonging to the peritoneum 

 Peritoneum. A thin, smooth, lubricous 

 membrane investing the whole internal 

 surface of the abdomen, and, more or 

 less completely, all the viscera con- 

 tained in it. 



Peritrema. The raised margin which 

 surrounds the breathing-holes of scor- 

 pions. 



Petaloid. Having the form of petals. 

 Petiolate. Supported or suspended by a 



slender stalk. 

 Petrescence. The process of changing 



into stone. 



Petrifactive ; Petrific. Having power to 

 convert animal or vegetable substan- 

 ces into stone. 

 Pharyngeal ; Pharyngal. Belonging to 



the pharynx. 



Pharynx. The opening into the gullet. 

 Phenomenon (pi. Phenomena). Any thing 

 which has existence in the natural 

 world ; as, the phenomena of heat, the 

 phenomena of the heavenly bodies, or of 

 terrestrial substances. 

 Phocenic. Appertaining to the dolphin. 



Phosphorescent. Shining in the dark, 



like the glowworm. 

 Physiological. Relating to the properties 



and functions of living beings. 

 Phytivorous. Feeding on plants and 



herbage. 



Phytophagous. Feeding on plants. 

 Piceous. Shining reddish-black, the 



color of pitch. 



Pilose. Covered with a thick down. 

 Pinion. To confine by binding the 

 wings. The joint of a fowl's wing, re- 

 motest from the body. 

 Pinnate. Shaped like a feather, or pro- 

 vided with fins. 

 Pinnated. Fin-footed ; having the toes 



bordered by membranes. 

 Pisciform. Having the shape of a fish. 

 Pisiform. Having the form of a pea. 

 Pistillaceous. Growing on the germ or 



seed-bud of a flower. 

 Pituitous. Consisting of mucus, or re- 

 sembling it in qualities. 

 Placenta. The substance that connects 

 the foetus to the womb, and by which 

 the circulation is carried on between 

 the parent and the foetus. 

 Placental. Pertaining to the substance 



that connects the foetus to the womb. 

 Plane. Perfectly level. When there is 



neither elevation nor depression. 

 PlanorUcular. Flat and circular. 

 Piano-subulate. Smooth and awl-shaped. 

 Plantigrade. When the whole or part of 

 the sole of the foot is placed flat on 

 the ground in walking, as is the case 

 with certain carnivorous Mammalia. 

 Plasma. The liquor sanguinis, or fluid 

 part of the blood, in which the red 

 corpuscles float. 

 Plastron. The under part of the shell of 



the crab and tortoise. 

 Pleiocene. The more recent tertiary stra- 

 ta, in which the major part of the fos- 

 sil Testacea belong to recent species. 

 Pleistocene. The newest of the tertiary 

 strata, which contains the largest pro- 

 portion of living species of shells. 

 Plexiform. In the form of network; 



complicated. 

 Plexus. A bundle of nerves or vessels 



interwoven or twined together. 

 Plicce. Folds of membrane. 

 Plicate; Plicated. Plaited; folded like 



