570 GLOSSARY 



Progesterone (pro-jes'-ter-on), female hormone secreted by the corpus luteum. 



Progestin (pro-jes'-tin), hormone secreted by the corpora lutea. 



Proglottid (pro-glSt'-tid), a segment of a tapeworm's body. 



Prophase (pr5'-faz), the first phase of mitosis. 



Protoplasm (pro'-to-plazm), the living matter within the cell. 



Protopodite (pro-top'-o-dit), the portion of a biramous appendage that is at- 

 tached to the crustacean. 



Pseudocoel (su'-do-sel), false body cavity as found in the roundworms. 



Pseudopodium (su-do-pod'-i-Sm), a temporary appendage thrust out by certain 

 cells for the purpose of locomotion or feeding; found in Amebae and white 

 blood cells. 



Pubis (pub'-is), the anterior bone of the pelvic girdle. 



Pulmonary (pul'-mo-ner-i), pertaining to the lungs. 



Pupa (pu'-pa), the inactive stage which follows the larval stage in insects having 

 a complete metamorphosis. 



Pyloric (pi-lo'-rik), refers to the region where the stomach connects with the 

 intestine. 



Pylorus (pi-lo'-rus), the opening between the stomach and the small intestine. 



Radius (ra'-di-us), the shorter bone of the forearm. 



Regeneration (re-jen-er-a'-shun), the replacement of lost or injured parts by 



animals. 

 Renal (re'-nal), refers to the kidney. 



Retina (ret'-i-na), the inner light sensitive layer of the eye. 

 Ruminant (ru'-min-ant), an ungulate that chews a cud. 



Sacral (sa'-kral), pertaining to the region where the pelvic girdle and the 



vertebrae come together. 

 Sartorius (sar-to'-n-us), a leg muscle on the inner surface of the thigh. 

 Scapula (skap'-u-la), the shoulder blade. 



Schizocoel (skiz'-o-sel), a cavity arising by the splitting of a layer of mesoderm. 

 Sclerotome (skler'-o-tom), the inner portion of the somite which forms the 



vertebrae of vertebrates. 

 Sclera (skler'-a), the outer, white layer of the eye. 

 Scolex (sko'-lex), the "head" of a tapeworm. 

 Scrotum (skro'-tum), the sac in which the testes are suspended. 

 Semen (se'-men), sperm together with the fluid in which they are suspended 



for ejaculation; the spermatic fluid. 

 Semimembranosus (sem-i-mem'-bra-nd-sus), a large muscle found on the outer 



surface of the thigh. 

 Seminal (sem'-i-nal), pertaining to semen. 

 Septum sep'-tum), p. septa, an internal body partition. 

 Sinus (si'-nus), a cavity. 

 Somite (so-mit'), regularly arranged muscle segments, as found in embryonic 



chordates. 

 Species (spe'-shes), pi. species, a subdivision of genera; the second word of the 



scientific name of a plant or animal. 

 Spermatid (spur-ma-tid'), a cell produced by maturation divisions that is to 



become a sperm. 

 Spermatocyte (spur'-ma-to-sit), a male germ cell during maturation. 



