612 GLOSSARY 



-trope (trop). G.; a turning. 



-trophy (tro' fl). G.; nutrition. 



tropism (tro' piz'm). The automatic response of an organism to a stimulus; adj., 

 tropic (tro' pik). 



trypsin (trip' sin). An enzyme which changes proteins to amino acids and is pro- 

 duced by the pancreas. 



tundra (toon' dra). A level, or gently undulating, treeless plain characteristic of the 

 arctic regions of both hemispheres. 



tympanum (tim' pa niim). In vertebrate anatomy, the cavity of the middle ear; 

 in zoology, the term is generally applied to any organ for the reception of sound 

 waves and frequently to a membrane having that function; adj., tympanic 

 (t!m pan' Ik). 



Tyndall (tin' dal), John. English physicist; 1820-1893. 



Umbilical (um bll' I kal) cord. The cord that unites a mammalian fetus to the 



placenta. 

 umbilicus (um bll' I kGs). The poiat of attachment of the umbilical cord to the young 



animal. 

 uncinate (tin' sin at). Hooked, 

 imguiculate (tin gwlk' il lat). Clawed, 

 imiparental (u nl pa r6n' tal). Involving only one parent, 

 imit character. A hereditary character that behaves as a unit in its transmission to 



offspring. 

 urea (u re' a). The substance which contains most of the nitrogenous waste of the 



animal body; adj., uric (u' rik). 

 ureter (u re' ter). The duct leading from the kidney and conveying the urine either 



to a urinary bladder or to the outside. 

 urethra (u re' thra). The duct from the urinary bladder to the external surface; adj., 



urethral, 

 uterus (u' ter iis). A dilated portion of the oviduct in which egg cells are retained 



while undergoing more or less of their development; adj., uterine (u' ter In). 



Vaccine (vak' sen). Any substance introduced into the animal body to protect it 



from infection. 

 vacuole (vak' u ol). A space in the cytoplasm of a cell usually filled with liquid and 



containing food or collecting liquid wastes to be eliminated. 

 vagina (va ji' na). The passage found in the female of many animals leading from 



the uterus to the outside; adj., vaginal (vaj' I nal). 

 vas (vas). L.; vessel. 



vascular (vas' ku lar). Pertaining to vessels, especially blood vessels. 

 vas deferens (vas d6f' er gnz). The duct leading from the testis to the outside; 



plural, vasa deferentia (va' sa d6f er gn' shI a). 

 vas efferens (vas 6f' er gnz). One of a number of small ducts interposed between the 



testis and the vas deferens; plural, vasa efferentia (va' sa 6f er 6n' shI a), 

 vein. A vessel conveying blood toward the heart; adj., venous (ve' ntis). 

 velum (ve' lum). An annular membrane projecting inward from the margin of the 



umbrella of certain medusae. 

 ventricle (v6n' tri k'l). A chamber in a heart from which blood is sent out; also a 



chamber in the vertebrate brain, 

 ventre (v6n' tr6). L.; belly. Adj., ventral. 

 verm (viirm). L.; worm. 



vermiform appendix. The contracted end of the caecum in primates, 

 vertebra (vllr' tg bra). One of the bones of the vertebral column, or backbone, in 



vertebrates; adj., vertebral (vAr' t6 bral). 



