672 



COLLEGE ZOOLOGY 



Eu-sta'chi-an tube (After Eustachi, Italian 

 physician. L. tuba, pipe). The tube leading 

 from the middle ear to the pharynx in higher 

 vertebrates. 



Eu-then'ics (Gr. euthenein, to thrive). The 

 science of improving the human species by 

 providing the best possible environment. 



E-vag'i-na"tion (L. e, out; vagina, sheath). 

 An outpocketing from any surface by growth, 

 especially a cavity. 



E-vis'cer-ate (L. ex, out; viscera, entrails). To 

 remove the internal organs. 



Ev'o-lu"tion, or-gan'ic (L. evolvere, to unroll. 

 Gr. organon, instrument, tool). The process 

 by which organisms have changed through 

 time, both structurally and functionally; 

 hence, descent with change has made pos- 

 sible the change of organisms from simple 

 to complex forms. 



Ex-cre'tion (L. ex, out; cernere, to sift). The 

 discharge of metabolic wastes; also the sub- 

 stance discharged. 



Ex-op'o-dite (Gr. exo, outside; pons, foot). 

 The external branch of a typical biramous 

 crustacean appendage. 



Ex'o-sker'e-ton (Gr. exo, outside; skeletos, 

 hard). A supporting structure on the out- 

 side of the body of an animal. The skeleton 

 of an invertebrate is usually an exoskeleton. 



Ex'pi-ra"tion (L. ex, out; spirare, to breathe). 

 The expulsion of water or air from the lungs 

 in a vertebrate. 



Ex-ten'sor (L. ex, out; tendere, to stretch). 

 Any muscle that straightens out or extends 

 a part of the body such as a foot. The op- 

 posite of flexor. 



Ex-ter'nal res'pi-ra"tion. Consists of 2 phases: 

 ( 1 ) breathmg, which brings air and blood 

 together in the lungs, and (2) the trans- 

 portation of oxygen and carbon dioxide be- 

 tween the lungs and cells. 



Fac'et (L. fades, face). The external surface 

 of an individual ommatidium. 



Fam'i-ly (L. familia, from faviulus, servant). 

 The principal subdivision of an order. 



Fas'ci-a (L., band). A band of connective tis- 

 sue that covers and supports or binds parts 

 together. 



Fau'na (L. f annus, a god of the woods). A 

 term referring to animal life of a given pe- 

 riod or region. 



Fe'ces (L. faeces, dregs). The indigestible, 

 unabsorbed residue of digestion. 



Fe'mur (L. femur, thigh). The thighbone; ad- 

 jective form is femoral. 



Fer'ti-li-za"tion (L. fertilis, from ferre, to 

 bear). The union of a mature ovum and a 

 mature sperm to form a zygote. 



Fe'tus (L., a bringing forth). The advanced 

 stages of a mammalian embryo. 



Fi-brin'o-gen (L. fibra, band; Gr. gignesthai, 

 to produce). A protein substance in the 

 blood that is changed to fibrin during clot- 

 ting. 



Fis'sion (L. fissus, cleft). An asexual method 

 of reproduction by division into two or more 

 parts approximately equal in size. 



Fis'sure (L. fissus, cleft). A furrow, cleft, or 

 slit. 



Fla-gel'lum (L. fiagellum, whip). A long whip- 

 like cytoplasmic process of a cell or a single- 

 celled animal, capable of vibration. 



Flex'or (L. fiexus, bent). A muscle whose func- 

 tion is to bend or flex a joint, thereby 

 decreasing the angle between the two com- 

 ponent parts. 



Fol'li-cle (L. folliculus, small sac). A cellular 

 sac or covering. 



Fo-ra'men (L. foramen, an opening). A nat- 

 ural opening in a bone or membrane through 

 which blood vessels and/or nerves usually 

 run. 



Fo-ra'men of Mun-ro' ( L. from forare, to bore, 

 pierce. After Alexander Munro). A passage- 

 way between the lateral ventricles and third 

 ventricle of the brain. 



Fos'sa (L. fossa, ditch). A pit or depression 

 in a bone. 



Fos'sil (L. fossilis, from fodere, to dig). The 

 remains or other indications of prehistoric 

 forms of life. 



Free'-liv'ing. Not parasitic or attached. Com- 

 pare with Parasite and Sessile. 



Fron'to-pa-ri"e-tal (L. frons, forehead; paries, 

 wall). One of the long flat bones forming 

 the roof of the cranium, as in the frog. 



Func'tion (L. fungi, to perform). The action 

 of any part of a plant or animal. 



Gam'ete (Gr. gametes, spouse). A mature re- 

 productive or germ cell, either ovum (egg), 

 sperm, or other t}'pe of reproductive cell. 



Gam'-e-to-gen"e-sis (Gr. gametes, spouse; 



