PER- 



233 



PER- 



peridenn (pgr'idgrm) n. [Gk. peri, 

 round ; derma, skin.] The outer 

 layer of bark (dot.} ; the external 

 cuticular layer of Hydrozoa (zool.}. 

 peridesm (pgr'idgzm) n. [Gk. peri, 

 round ; desme, a bundle.] Tissue 

 surrounding a vascular bundle (bot.}. 

 peridesmium (pgr'fdgz'mium) n. [Gk. 

 peri, round ; desmos, a band.] 

 Tissue surrounding a ligament 

 (anat.}. 



peridlal (perld'ial) a. [Gk. peridion, 

 a small wallet.] Pert, a peridium 

 (bot.}. 



perididymis (pgr'idid'imTs) n. [Gk. 

 pert, round ; didymos, a testicle.] 

 The fibrous covering of the testis 

 (anat.}. 



peridiolum (pgrid'iolum) n. [Gk. 

 peridion, a small wallet.] A small 

 peridium or collection of spores 

 enclosed within the peridial covering 

 (bot.}. 



peridium (pgrid'ium) n. [Gk. peridion, 

 a small wallet.] The coat investing 

 the sporophore of Fungi ; the outer 

 covering of a puff-ball (dot.}. 

 peridural (pgrtdu'ral) a. [Gk. peri, 

 round ; L. durus, hard.] Appl. the 

 perimeningeal space at a later stage 

 of development (emb.}. 

 perienteric (pgrtgn'tgrik) a. [Gk. 

 peri, round ; enteron, the gut.] Sur- 

 rounding the enteron (zool.}. 

 perienteron (pgrtgn'tgron) n. [Gk. 

 peri, round ; enteron, gut.] A 

 cavity surrounding the enteron or 

 visceral cavity (emb.}. 

 perifbliary (pgrWliari) a. [Gk. peri, 

 round ; L. folium, a leaf.] Round 

 a leaf margin (bot.\ 

 perigastric (pgr'igas'trlk) a. [Gk. 

 peri, round ; gaster, stomach.] 

 Surrounding the viscera ; appl. the 

 abdominal cavity. 



perigastrula (per'igas'troola) n. [Gk. 

 peri, round ; gaster, stomach.] 

 The gastrula resulting after super- 

 ficial segmentation (emb.}. 

 perigonium (peVigo'nlum) n. [Gk. 

 peri, round ; gone, generation.] A 

 floral envelope or perianth ; the 

 involucre round the antheridium of 

 Mosses (bot.} ; a gonotheca (zool.}. 

 perigynium (pSr'fjTn'Ium) n. [Gk. 

 peri, round ; gyne, a female.] The 

 fruit-investing utricle of the genus 



Carex ; the membranous perianth 

 of Mosses (bot.}. 



perigynous (pgrlj'mus) a. [Gk. peri, 

 round ; gyne, female.] Having 

 sepals, petals, stamens round the 

 gynoecium, not underneath ; cf. 

 hypogynous (bot.}. 



perigyny (pgrij'inl) n. [Gk. peri, 

 round ; gyne, a female.] Arrange- 

 ment in a perigynous manner. 

 perihaemal (peYlhe'mal) a. [Gk. 

 peri, round ; haima, blood.] Appl. 

 the blood-vascular system of canals 

 and spaces of Echinoderms ; appl. 

 dorsal outgrowths of the third body- 

 cavity of Enteropneusta (zool.}. 

 perilymph (peYllimf) n. [Gk. peri, 

 round ; L. lympha, water.] A fluid 

 separating the membranous from 

 the osseous labyrinth of the ear 

 (anaf.}. 



perimedullary (peYime'duTari) a. 

 [Gk. peri, round ; L. medulla, the 

 marrow.] Surrounding the pith of 

 a stem ; appl. a zone (bot.}. 

 perimeningeal (pgr'imgnTn'jeal) a. 

 [Gk. peri, round ; meningx, a mem- 

 brane.] Appl. a space between the 

 endorhachis and the meninx primi- 

 tiva or spinal cord envelope (emb.}. 

 perimysium (pgrTmiz'ium) n. [Gk. 

 peri, round ; mys, a muscle.] Con- 

 nective tissue binding numbers of 

 fibres into bundles and muscles, 

 and continuing into the tendons ; 

 alternatively, appl. only to fasciculi 

 envelopes ; cf. epimysium (anaf.}. 

 perinaeal (pgr'Ine'al) a. [Gk. peri- 

 naion, the part between anus and 

 scrotum.] Pert, the perinaeum ; 

 appl. artery, body, nerve (anat.}. 

 perinaeum (pgr'Ine'um) n. [Gk. peri- 

 naion, the part between anus and 

 scrotum.] A surface of the body 

 limited by the scrotum in front, the 

 buttocks behind, and laterally by 

 the medial side of the thigh (anaf.}. 

 perinephrium (pgr'ingf'rlum) n. [Gk. 

 peri, round ; nephros, kidney.] The 

 enveloping tissue of the kidney 

 (anaf.). 



perineurium (pgr'inu'rlum) n. [Gk. 

 pert, round ; neuron, a nerve.] The 

 tubular sheath of a small bundle of 

 nerve fibres (anat.}. 

 perinium (pgrln'fum) n. [Gk. peri, 

 round ; is, a fibre.] An epispore, 



