VIL- 



346 



VIT- 



villiform (vil'iform) a. [L. villus, 

 shaggy hair ; forma, shape.] Hav- 

 ing the form or appearance of 

 velvet ; appl. dentition (zool.). 



villous (vil'us) a. [L. villus, shaggy 

 hair.] Pubescent (hot.) ; having 

 villi or covered with villi (zool.). 



vlllus (vil'us) n., villi (vil'l) plu. [L. 

 villus, shaggy hair.] Trophonemata 

 or minute vascular processes on the 

 intestine lining ; processes on the 

 chorion through which nourishment 

 passes to the embryo (anat.) ; fine 

 straight processes on the epidermis 

 of plants (hot.}, 



vimen (vl'me'n) n., vimina (vim'ina) 

 plu. [L. vimen, twig.] A long 

 slender shoot or branch (hot.). 



vinculum (ving'kulum) n., vincula 

 (ving'kula) plu. [L. vinculum t 

 chain.] Slender tendinous bands ; 

 accessory connecting bands of fibres, 

 as vincula brevia (anat.) ; a band 

 uniting the two main tendons of 

 the foot in Birds (zool.). 



virescence (virfis'fins) n. [L. virescere, 



to grow green.] The production of 



. green colouring matter in petals 



instead of the usual colouring 



matter (hot.). 



virgate (veYgat) a. [L. virga, twig.] 

 Rod-shaped. 



virginal (ver'jTnSl) a. [L. virgo, 

 virgin.] Appl. female which repro- 

 duces parthenogenetically (zool.}. 



virgula (ver'gulS) n. [L. virga, rod.] 

 A small rod, the axis of a Grapto- 

 lite. 



viscera (vis'erii) n. plu. [L. viscera^ 

 bowels.] The internal organs con- 

 tained in the various cavities of the 

 body (anat.). 



visceral (vis'eral) a. [L. viscera, 

 bowels.] Pert, the viscera ; appl. to 

 numerous structures and organs 

 (anat.). 



visceral arches, a series of arches 

 developed in connection with the 

 mouth and pharynx (zool.). 



visceral clefts, a series of furrows 

 or clefts on the neck region be- 

 tween successive visceral arches, 

 which may or may not place the 

 pharynx in direct communication 

 with the exterior (anat.). 



visceromotor (vls'erom6't6r) a. [L. 

 viscera, bowels ; movere, to move.] 



Carrying motor impulses to the 

 viscera (phys.). 



viscosity (viskos'itl) n. [L. viscosus, 

 viscous.] The internal friction in 

 liquids due to the adherence of 

 particles to one another (phys.). 



visitant (viz'Itant) . [L. visere, to 

 go to see.] Term appl. a bird 

 which is not an inhabitant of a 

 certain region, but appears at stated 

 periods in that region (zool.). 



visual purple, seerhodopsin (phys.). 



vital force, the peculiar form of 

 energy manifested in living phe- 

 nomena when considered distinct 

 from chemical, physical, and 

 mechanical forces (biol.). 



vital functions, the functions of the 

 body on which life depends (phys.). 



vitalism (vl'talizm) n. [L. vita, life.] 

 The belief that the various phe- 

 nomena exhibited in living organ- 

 isms are due to a special force 

 quite distinct from physical forces 

 (biol.\ 



vitamines (vl'taminz) n. plu. [L. 

 vita, life ; ammoniacum, resinous 

 gum.] Active substances whose 

 absence in diet causes disease, 

 as in beri-beri ; basic nitrogenous 

 substances occurring in varying 

 amounts in different foods (phys.). 



vitellarium (vit'ela'rium) a. [L. 

 vitellus, yolk.] A special organ in 

 Flatworms and many Rotifers which 

 produces yolk-laden cells (zool.). 



vitelligenous (vit'glij'eniis) a. [L. 

 vitellus, yolk ; gignere, to beget.] 

 Producing yolk ; appl. cells in the 

 ovary of many Insects (zool.). 



vitellin (vitgl'Tn) n. [L. vitellus, 

 yolk.] The phospho-protein of egg- 

 yolk (phys.) ; a similar or related 

 substance in seeds (hot.). 



vitelline (viteTin) a. [L. vitellus, 

 yolk.] Pert, the yolk, or yolk- 

 producing organ ; appl. artery, 

 vein, duct (zool., emb.). 



vitellophags (vitgl'ofagz) n. plu. [L. 

 vitellus, yolk ; Gk. phagein, to eat.] 

 Isolated cells forming the hypoblast 

 of Crustacean egg (zool.). 



vitellose (viteTos) n. [L. vitellus, 

 yolk.] A substance formed in the 

 digestion of yolk (phys.). 



vitellus (vlteTus) n. [L vitellus, 

 yolk.] The yolk of an egg (emb.). 



