=Tu-ni-ca´ta= [Lat. _tunica_, tunic.] A class of Chordata called Sca-squirts or Ascidians. =Tynes= [AS. _tind_, prong.] The spike or prong of an antler. =Un-gu-la´ta= [Lat. _unguis_, nail.] The order of hoofed mammals. =U-ro-de´la= [Gr. _oura_, tail; _delos_, manifest.] The tailed Amphibians. =U´te-rus= [Lat. _uterus_, womb.] The organ of a female animal in which the young are protected and developed before birth. =Vac´u-ole= [Lat. _vacuus_, empty.] The little cavities in cells containing watery solutions. =Ves´i-cle= [Lat. _vesicula_, little bladder.] Synonymous with vacuoles. =Ve´na ca´va= [Lat.] _Hollow vein._ Either of the two great veins that empty into the right auricle of the heart. =Ven´tri-cles= [Lat. _ventriculus_, little belly.] One of the cavities of the heart or brain. =Ven´tral= [Lat. _venter_, belly.] Applied to the front (under) side of the body. =Ver´mes= [Lat. _vermis_, worm.] =Ver-te-bra´ta= [Lat. _vertebratus_, jointed.] =Ver´te-brate= [Lat. _vertebratus_, jointed.] =Vi-vip´a-rous= [Lat. _vivus_, alive; _pario_, bear.] Applied to animals which bring forth their young alive. =Vis´ce-ra= [Lat. _viscera_, organs.] The internal organs of the body. =Vol´vox glo-ba´tor= [Lat. _volvo_, roll; _globatus_, made into a ball.] =Wat´tles= [AS. _watel_, hurdle.] Fleshy, naked processes depending from the neck or head of a bird. FOOTNOTES. [1] One cubic millimeter of human blood alone, not to mention other tissues of the body, contains over five million cells. [2] Except in the maturation of _ova_ and _spermatozoids_. [3] Bradford. [4] Bradford. [5] Socially, morally, and religiously. [6] Lyell. [7] Readers not familiar with Elementary Zoölogy will do well to consult the Classification of Animals in Section VII.; and also the Diagram of Development. [8] Wallace. [9] Belt. [10] Wallace. [11] Wallace. [12] Wallace. [13] Darwin. [14] Darwin. [15] Lloyd Morgan. [16] Clodd. [17] “Feelings and motions run parallel to each other, and where we do not meet with actual feelings we suppose the presence of the elements of feeling. But this parallelism would be most wonderful indeed if it were a true parallelism consisting of two different and distinct lines. The simplest conception of the case is the monistic view, which considers the parallelism as an identity. Both motion and feeling are abstract conceptions. A motion exists of itself no more than a feeling. The reality from which the ideas motion and feeling have been abstracted is one inseparable whole, which if viewed as an objective process appears as motion, and if viewed from the subjective side appears as feeling. Feelings can only be felt, not seen; but if we _could_ see them, we might observe the elements of feeling wherever motion takes place.