274 GLOSS AST. 



Epizoic. Parasitic on an animal. 



Ethmoid. A bone between the two orbits. 



Ethnology. The science of Race. The study of the varieties of 

 mankind. 



Etiology. See JEtiology. 



Etology. The study of the general laws that contribute to form 

 the character of individuals and communities. 



Evolution. The descent of species, " each within its own class or 

 group, from common parents" (Darwin}. "A change from 

 indefinite, incoherent homogeneity, to a definite coherent he- 

 terogeneity, through successive differentiations and integra- 

 tions " (Herbert Spencer). " Evolution teaches us that at a 

 certain period in the history of this planet such albuminoid 

 substances as protoplasm came, by gradual building up, into 

 existence" (Ray Lankester}. "The only perfectly sate founda- 

 tion for the doctrine of Evolution lies in the historical, or 

 rather archaeological, evidence that particular organisms have 

 arisen by the gradual modification of their predecessors, which 

 is furnished by fossil remains " (Huxley}. The difficulty of 

 explaining the existence of the myriads of lowest and almost 

 structureless animals has led Dr. Bastian and others to the 

 belief that " living matter is continually coming into being." 



Exocorium. The narrow portion of the hemelytron of certain 

 Hemiptera bordering the corium externally. 



Exogenous. A term applied to bones that are developed from 

 previously ossified parts. 



Exoplasm. An expansion of the so-called cuticle in certain Pro- 

 tozoa. 



Exopodite. An inner filamentous appendage attached to the 

 basal joint of certain Crustacea. 



Exoskeleton. The external hard integument of animals. 



Exothecce represent externally the dissepiments in the thecae of ; 

 corallite in some Zoantharia. 



External influences. See Environment. 



FabellcB. Sesamoid bones in the gastrocnemius muscle of 



dog. 

 Fades. The face, also the outside figure (statura or habitus} ; in 



the latter sense Huxley proposes the word "Metope" 

 Falces. The poison-fangs of spiders. 

 Femur. The thigh-bone. 



