238 VOCABULAllY. 



organs. Prof. Cope says : " Every individual of every species 

 of a given brancli of the animal kingdom is composed of ele- 

 ments common to all, and the diiForcaces wliicii are so radi- 

 cal in the higher grades are but the modifications of the same 

 elemental parts." E. L. Toumans. 



Exfolia'tiqn (from ex andi folium, ' a leaf). By this is meant 

 the separation of the dead portions of a bone, tendon, apon- 

 eurosis (a white shining membrane), or cartilage, under the 

 form of lamelke (small scales). Exfoliation is accomplished 

 by the instinctive action of the parts, and its object is to de- 

 tach the dead portions from those subjacent, which are still 

 alive. For this purpose the latter throw out fleshy granula- 

 tions, and a more or less abundant suppuration occurs, which 

 tends to separate the exfoliated part — now become an extra- 

 neous body. 



Exosro'sis. An osseous tumor, which forms at the surface of 

 bones, or in their cavities. 



ExosTOiis Dentium. Exostosis of the teeth. 



F. 



Ferru'ginous (chalyb'eate). Of or belonging to iron ; contain- 

 ing iron. Any medicine into which iron enters, as chalyb- 

 eate mixture, pills, waters, &c. 



Fe'tus. See ' embryo.' 



Fiber. An organic filament, of a solid consistence, and more or 

 less extensible, which enters into the composition of every 

 animal and vegetable texture, 



Fil/'ament. a thread. This word is used synonymously with 

 fibril ; thus we say a nervous or cellular filament or fibril. 



Fis'tula. ' A pipe or reed.' A solution of continuity (a division 

 of parts previously continuous) of greater or less depth and 

 sinuosity, the opening of which is narrow, and the disease 

 kept up by an altered texture of parts, so that it is not dis- 

 posed to hoal. A fistula is ' incomplete ' -or ' blind' when it 

 has but one opening, and ' complete ' when there are two, the 

 one communicating Avith an internal cavity, the other exter- 

 nally. It is lined in its whole course by a membrane which 

 seems analogous to mucous membranes. 



Fol'ltcle. a follicle or cryi)t is a small, roundish, hollow 

 bodv, situate in the substance of the skia or mucous mem- 

 branes, and constantly pouring the fluid which it secretes on 



