PER- 



232 



PER- 



through ; annus, year.] Persisting 

 through the year or for a number 

 of years (tot.). 



perennibranchiate (pgren'ibrang'kTat) 

 a. [L. per, through ; annus, year ; 

 Gk. brangchia, gills.] Having 

 gills persisting throughout life, as 

 certain Amphibians (zoo/.). 



perfoliate (pgrfo'Hat) a. [L. per, 

 through ; folium, leaf.] Appl. a 

 leaf with basal lobes so united as 

 to appear as if the stem ran through 

 it (tot.). 



perforate (per'forat) a. [L. perforare, 

 to bore through.] Having holes 

 or pores, as Corals, Foraminifers 

 (zool.) ; appl. certain areas of the 

 brain perforated by small blood- 

 vessels (anat.). 



perforator (pgr'fora'tor) n. [L. per- 

 forare, to bore through.] A barbed 

 spear-like head and process of some 

 spermatozoa, as of Salamander 

 (*ooL\ 



perhydridase (pgrhl'dridas) n. [L. 

 per, through ; Gk. hydor, water.] 

 An enzyme which causes the 

 activation of perhydride hydrogen 



perianth (per'ianth) n. [Gk. peri, 

 round ; anthos, flower.] A floral 

 envelope ; the external floral whorls, 

 including calyx and corolla (tof.). 



periblast (pgr'iblast) n. [Gk. peri, 

 round ; blastos, a bud.] The outside 

 layer, epiblast, or blastoderm of an 

 insect embryo (emb.}. 



periblastic (pgriblas'tlk) a. [Gk.peri, 

 round ; blastos, a bud.] Pert, the 

 periblast ; superficial, as appl. 

 segmentation (emb.}. 



periblastula (pgr'iblas'tula) n. [Gk. 

 Peri, round ; blastos, bud.] A blastula 

 resulting from periblastic segmenta- 

 tion (emb.}. 



periblem (pgrTblgm) n. [Gk. peri, 

 round ; blema, a coverlet.] Layers 

 of ground or fundamental tissue 

 between dermatogen and plerome 

 of growing points (tot.). 



peribranchial (pgr'ibrang'klal) a. [Gk. 

 peri, round ; brangchia, gills.] 

 Around the gills ; appl. a type of 

 gemmation and an atrial cavity in 

 Ascidians ; appl. circular spaces 

 surrounding basal parts of papulae 

 of Asteroids (zoo/.). 



pericardiac (per'fkar'diak), peri- 

 cardial (pgrTkar'dial) a. [Gk. peri, 

 round ; kardia, heart.] Pert, the 

 pericardium ; surrounding the 

 heart ; appl. cavity, septum (anat.}. 



pericardium (pgrTkar'dium) n. [Gk. 

 peri, round ; kardia, heart.] The 

 cavity containing the heart ; the 

 membrane enveloping the heart 

 (anat.}. 



pericarp (pgr'ikarp) n. [Gk. peri, 

 round ; karpos, fruit.] The ovary 

 walls of fruits (tot.). 



pericentral (pgr'isen'tral) a. [Gk. 

 peri, round ; L. centrum, centre.] 

 Round or near the centre ; appl. 

 auxiliary cells (tot.}. 



perichaetium (pgr'ike'shlum) n. [Gk. 

 peri, round ; chaite, loose hair.] 

 One of the membranes enveloping 

 the archegonia of Mosses (tot.). 



perichondrium (pgr'ikon'drium) n. 



fGk. peri, round ; chondros, carti- 

 age.J A fibrous membrane that 

 covers cartilages (anat.}. 

 perichordal (per'ikor'dal) a. [Gk. 

 peri, round ; chorde, a cord.] 

 Enveloping or near the notochord 

 (zool.). 



perichylous (pgr'iki'lus) a. [Gk. peri, 

 round ; chylos, juice.] With water- 

 storage cells outside the chlor- 

 enchyma (tot.). 



pericladium (per'ikla'dium) n. [Gk. 

 Peri, round ; klados, a branch.] 

 The lowermost clasping portion of 

 a sheathing petiole (tot.). 



periclinal (pgr'ikll'nal) a. [Gk. peri, 

 round ; kleiein, to surround.] Appl. 

 the system of cells parallel to the 

 surface of the apex of a growing 

 point (tot.}. 



periclinium (pgr'Iklin'ium) n. [Gk. 

 Peri, round ; kline, a bed.] The 

 involucre of a composite flower 

 (tot.). 



pericranium (pgr'ikra'nium) n. [Gk. 

 peri, round ; kranion, skull.] The 

 fibrous membrane investing the 

 skull (anat.}. 



pericycle (pgr'isfkl) n. [Gk. peri, 

 round ; kyklos, a circle.] The 

 external layer of the stele (tot.). 



peridental (pgrTden'tal) a. [G\L.peri, 

 round ; L. dens, tooth.] Investing 

 a tooth ; appl. a membrane, or the 

 periosteum of a root (anat.}. 



