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PER 



pergamentaceous, a., perg'-a-ment- 

 d'shus (L. pergamena, parch- 

 ment), of the texture of parch- 

 ment. 



perianth, n., p&r'-l-anili (Gr. peri, 

 around ; antlws, a flower), in 

 bot., a general name for the 

 floral envelope ; the external 

 floral whorls which surround the 

 stamens and pistil in this sense 

 including calyx and corolla. 



periblem, n., per'-i-blZm (Gr. 

 periblema, clothing, a cloak 

 from peri, around ; ballo, I 

 throw), in lot., a collection of 

 layers of cells beneath the der- 

 matogen out of which the cortex 

 arises. 



pericambium, n., per'-i'lcamf-bi-um 

 (Gr. peri, around ; new L. cam- 

 bium, nutriment ; L. cambid, I 

 change), in bot., the outer layer 

 of the plerome. 



pericardium, n., per'-i-hard'-i-urn 

 (Gr. peri, round about ; kardid, 

 the heart), the membranous bag 

 which surrounds and encloses the 

 heart : pericardiac, a., p'er'-i' 

 kdrd'i-ak, of or pert, to the 

 pericardium : pericarditis, n., 

 p'er'-i-kdrd-it'-is, inflammation of 

 the membrane which surrounds 

 the heart. 



pericarp, n., pZr^i'kdrp (Gr. peri- 

 karpion, the covering of seed 

 from peri, around ; karpos, 

 fruit), the part of the fruit 

 immediately investing the seed ; 

 the covering, shell, or rind of 

 fruits : pericarpial, a., p$r f 4- 

 kdrp'-i-al, of or pert, to a peri- 

 carp. 



perichsetium, n., p^r'-i-ke'-shi-tim 

 (Gr. peri, round about ; chaite, 

 long loose flowing hair, as of the 

 mane of a horse), the leaves that 

 surround the base of the fruit- 

 stalk of some mosses: perichsetial, 

 a., per'i'ke'shi-al, pert, to the 

 perichsetium. 



perichondrium, n., p'er'i>'k8nd'-r ! t< 

 urn (Gr. peri, round about ; 

 chondros, cartilage), in anat., a 



fibrous membrane which covers 

 cartilages. 



pericladium, n., p^r'-i-ldad'-l-um 

 (Gr. peri, round about ; klados, 

 a branch), in bot. , the lowermost 

 clasping portion of sheathing 

 petioles ; the large sheathing 

 petiole of Umbelliferse. 

 periclinium, n., per'i-klm'i-um 

 (Gr. peri, round about ; kline, a 

 bed), in bot., the involucre of 

 composite flowers. 

 pericranium, n., per'i'krdn'$-um 

 (Gr. peri, round about ; kranion, 

 the skull), the fibrous membrane 

 which goes round or invests the 

 skull, and corresponds to the 

 periosteum of other bones. 

 periderm, n., per'-i-derm (Gr. 

 peri, round about ; derma, skin), 

 in bot., the outer layer of bark ; 

 the stratified cork envelope which 

 replaces the epidermis in parts of 

 vigorous growth ; in zool., the 

 hard cuticular layer which is 

 developed by the Coanosarc of 

 certain of the Hydrozoa. 

 peridium, n., per-id'-i-urn (Gr. 

 perideo, I wrap round), in bot., 

 the coat immediately enveloping 

 the sporules of the lower tribes 

 of acotyledons ; a covering, as of 

 a puff-ball : peridiola, n. plu. , 

 p%r f -id'i f '8l'a (L. dim. of peridium), 

 a number of small peridia inclosed 

 in a general covering. 

 perigastric, a. , pZr'-i-gasMk (Gr. 

 peri, round about ; gaster, the 

 belly), in zooL, applied to the 

 cavity which surrounds the 

 stomach and other viscera, 

 corresponding to the abdominal 

 cavity in the higher animals, 

 perigone, n., p&r'i-gon (Gr. peri, 

 round about ; goneus, a parent ; 

 gune, a female), a floral envelope; 

 a synonym for perianth, especially 

 when reduced to a single floral 

 whorl : perigonium, n. , pbr'*i> 

 gdn'-i-um, a barren flower in 

 mosses having involucral scales. 

 perigynium, n., per'-i-jin'-i-urn 

 (Gr. peri, round about ; gunt t a 



