GLOSSARY 565 



Ebers (a' bers), Georg M. German Egyptologist; 1837-1898. 



ecdysis (6k di' sis). The shedding of the cuticula of an arthropod or of the horny 



scales of a snake or lizard. 

 economic (6 k6 nOm' 1k). Pertaining to utilitarian values, either positive or negative, 

 act- (fkt). G.; without, outside. 

 ectoderm (6k' t6 durm). The outer germ layer in embryogeny; adj., ectodermal 



(6k t6 dur' mal). 

 ectoplasm (6k' t6 plaz'm). The outer part of the cytoplasm of a protozoan; adj., 



ectoplasmic (6k to pLiz' mik). 

 effector (6f f6k' ter). A term applied to either a cell or an organ that completes a 



reflex act. 

 efferent (6f' fer 6nt). Outgoing, from a center. 

 egestion (e j6s' chun). The passing out of feces. 

 egg. An egg cell with its protective coverings. 

 egg cell. The female reproductive cell. 

 electrotropism (e l6k tr6t' ro piz'm). Response to an electrical stimulus; adj., 



electrotropic (e 16k tro tr6p' Ik). 

 elimination (e llm I na' shun). The passage out of the body of liquid waste; adj., 



eliminative (e llm' I na tlv). 

 embryo (6m' bri o). An animal in the early stages of its development; adj., embry- 

 onic (6m brI 6n' Ik). 

 embryogeny (6m bri 6j' 6 nl). The stages in the embryonic development of an 



animal. 

 Empedocles (6m ped' 6 klez). Greek philosopher; about 500-430 b.c. 

 en- (6n). G.; in. 



encephalon (6n s6f' ;i I6n). The brain of a vertebrate, 

 encystment (6n sist' m6nt). The formation of a hard covering, or cyst, about an 



organism. 

 endo- (6n' do), or ento- (6n' to). G.; within. 



endocrine (6n' do crin). Pertaining to internal secretions or ductless glands, 

 endomixis (6n d6 mik' sis). A process of reorganization of the nuclear material in a 



protozoan cell. 

 endoplasm (6n' d6 pliiz'm). The inner portion of the cytoplasm of a protozoan cell; 



adj., endoplasmic (6n do plaz' mIk). 

 endoskeleton (6n do sk6r e tun). An internal skeleton; adj., endoskeletal. 

 endothelium (6n d6 the' ll lim). An epithelium of mesodermal origin lining coelomic 



cavities, serous spaces, and blood and lymph vessels; adj., endothelial, 

 enteron (6n' ter 6n). A digestive cavity; adj., enteric (6n t6r' Ik). 

 entoderm (6n' t6 diirm). The inner germ layer; also called endoderm; adj. ento- 



dermal (6n t6 dur' mal). 

 entozoic (6n to zo' Ik). Living within an animal body, 

 enzyme (6n' zim). A catalytic ferment, 

 epi- (6p' I). G.; upon. 

 epibole (6p lb' 6 le). The growth of a fold of the blastoderm over the surface of the 



embryo, leaving an archenteron between the two. 

 epidermis (5p I dur' mis). The outer epithelial layer of the skin of vertebrates; adj. 



epidermal (6p i dur' mal). 

 epigenesis (6p I j6n' e sis). The conception that the parts of an organism arise from 



an undifferentiated germ cell, in contrast to the idea of preformation, 

 epithelium (6p I the' II um). A tissue covering a free surface; adj., epithelial, 

 epizoic (6p I z5' Ik). Living upon the surface of an animal. 

 equatorial (e kwa to' rl al) plate. The group of chromosomes lying in the equatorial 



plane of the spindle in mitosis. 



