698 



GLOSSARY 



time). Characterized by early matu- 

 rity. 

 Pre-da'ceous (L. praedo, prey). Capturing 



of live animals for food. 

 Pri-mor'di-al (L. primordium, beginning). 



Original or primitive. 

 Prin'ci-ple (L. principhim, beginning). Sci- 

 entific fact, theory, or law. 

 Pro-bos'cis (Gr. proboskis, trunk). Tubular 

 extension of the lips, nose, or pharynx. 

 Proc'to-de"um (Gr. proktos, anus; hodos, 

 way). The most posterior part of the 

 digestive tract near the anus, lined with 

 ectoderm. 

 Pro-neph'ros (Gr. pro, before; nephros, 



kidney). A primordial kidney. 

 Pro-nu'cle-us (Gr. pro, before; L. nucleus, 

 kernel). The nucleus of either the egg 

 or sperm cell during the interval ex- 

 isting between the penetration of the 

 sperm into the egg and the subsequent 

 union to form the germinal nucleus. 

 Pro'phrase ( Gr. pro, before; phasis, appear- 

 ance). The first stage of mitotic divi- 

 sion during which the chromosomes 

 become visible. 

 Pros'tate gland (Gr. prostates, one who 

 stands before; L. glans, an acorn). An 

 accessory sex gland found in the male 

 surrounding the neck of the bladder 

 and urethra. 

 Pro'te-in (Gr. protos, first). An organic 

 compound composed of amino acids 

 forming an essential part of the proto- 

 plasm. 

 Pro'to-plasm (Gr. protos, first; plasma, 

 something molded). The colloidal liv- 

 ing substance constituting the physical 

 basis of life. 

 Pro'to-zo"a (Gr. protos, first; zoion, ani- 

 mal). A phylum of animals. 

 Prox'i-mal (L. proximus, next). Near the 



point of attachment of an organ. 

 Pseu'do-coel ( Gr. pseudo, false; koilia, body 

 cavity). A body cavity not completely 

 lined with mesoderm, as found in the 

 round worm. 

 Pseu'do-po"di-a (Gr. pseudo, false; pous. 



foot). A temporary protoplasmic pro- 

 jection found in amoeba or in some 

 amoeba-like cells. 



Pty'a-lin (Gr. ptyalon, spittle). Salivary en- 

 zyme which acts on starch. 



Pu'bis (L. puhes, mature). The pubic bone, 

 one of the three bones forming the pel- 

 vis. 



Pul'mo-nar-y (L. pidmo, lung). Pertaining 

 to the lung. 



Py-lor'ic (Gr. pylorus, gate). Pertaining to 

 the posterior portion of the stomach or 

 the pylorus. 



Quad'ru-ped (L. quattuor, four; pes, foot). 

 Four-footed animal. 



Ra'di-al sy'me-try (L. radius, ray). The con- 

 dition in which similar parts are regu- 

 larly arranged around a central axis, 

 for example, as seen in starfish. 



Ra'mus ( L. ) . A branch, as of a blood ves- 

 sel, bone, or nerve. 



Re-cep'tor (L. receptor, receiver). A sen- 

 sory end organ. 



Rec'tum (L. rectus, straight). The most 

 posterior portion of the large intestine. 



Re-gen'er-a"tion (L. re, again; generare, to 

 beget). The renewal or repair of a 

 structure. 



Re'nal ( L. renes, kidney ) . Pertaining to the 

 kidney. 



Ren'nin (A.S. gerinnan, to curdle, coagu- 

 late ) . Enzyme secreted by the stomach 

 wall which causes the coagulation of 

 casein in milk. 



Re'pro-duc"tion (L. re, again; pro, forth; 

 ducere, to lead ) . The production of off- 

 spring. 



Res'pi-ra"tion (L. re, again; spirare, to 

 breathe). The gaseous metabolism at 

 the cellular level. 

 Re-sponse' ( L. re, again; spondere, to prom- 

 ise). Reaction to stimulus. 

 Ret'i-na (L. rete, net). The innermost layer 



