GLOSSARY 



689 



Ul'na (L. ulna, elbow) . The bone of the httle- 

 finger side of the forearm in the vertebrates 

 from amphibians to man, inclusive. 



Um-biri-cal cord (L. umbilicus, navel. Gr. 

 corde, string). The cordlike connection be- 

 tween the embryo or fetus of a mammal and 

 the placenta, composed mainly of blood ves- 

 sels and connective tissue. 



Un'gu-late (L. ungula, hoof). Having hoofs. 



Un'gu-li-grade' (L. ungula, hoof; gradi, to 

 walk). Walking or adapted for walking 

 on hoofs. 



U-re'a (Gr. oiiron, urine). The main nitrog- 

 enous metabolic waste of most mammals. 



U-re'ter (Gr. oureter, ureter). The tube that 

 carries urine away from the kidney to the 

 urinary bladder or the cloaca. 



U-re'thra (Gr. oureter, ureter). The duct that 

 carries urine from the bladder to the outside 

 in mammals. 



U'rine (L. urina, urine). The liquid waste 

 excreted by the kidneys. 



U'rin-if" er-ous tu'bule (L. urina, urine; ferre, 

 to bear. L. tubulus, any small tube). One of 

 the excretoiy tubules within the kidney of 

 higher animals, consisting of a coiled tube 

 and a capsule. 



U'ro-gen"i-tal ( U'ri-no-gen"i-tal sys'tem) (Gr. 

 ouron, urine; gignesthai, to produce. Gr. 

 systema, system ) . The organs of both the 

 urinary and the reproductive systems taken 

 collectively. 



U'ro-style (Gr. oura, tail; style, pillar). The 

 terminal, rodlike bone of the frog spinal 

 column. 



U'ter-us (L., womb). The enlarged portion of 

 an oviduct in which at least part of the de- 

 velopment of an animal takes place. Tech- 

 nically, the term uterus is applicable only to 

 animals in which the embryo becomes at- 

 tached to the wall of the organ. 



^^ac'u-ole (L. vacuum, empty). A small struc- 

 ture consisting of a cavity in the cytoplasm 

 filled with a liquid and/or other products. 



Va-gi'na (L., sheath) . The posterior part of the 

 female reproductive tract. It often receives 

 the copulatory organ of the male in mat- 

 ing. 



Va'gus (L., wandering). Tenth cranial nerve in 

 vertebrates. 



Va'ri-a'"tion (L. variare, to change). Difference 



in structure or function shown by individuals 

 of the same species. 



Va-ri'e-ty (L. varietas, difference). In taxon- 

 omy, a division of a species; a group of indi- 

 viduals within a single interbreeding popu- 

 lation that differs in some minor respect 

 from the rest of the species. 



Vas dc'fer-ens (L., vessel. L., carrying down). 

 A duct which carries sperms away from the 

 testis. 



Va'sa cf'fer-en'ti-a (L., vessels. L. efferens, 

 bringing out). Small ducts carr)ing sperms 

 from the testes to the kidney in the frog and 

 to the ductus epididymis or to other similar 

 tubules in higher animals. 



Vas'cu-lar (L. vasculum, little vessel). Per- 

 taining to vessels in animals; they usually 

 carry blood or lymph. 



Va'so-mo'tor nerves (L. vas, vessel; from 

 movere, motum, to move). Nerves which 

 control the contraction and expansion ot 

 blood vessels. 



Veg'e-tal hem'i-sphere (L. vegetare, to en- 

 liven. Gr. hemi, half; Gr. sphaira, ball). The 

 part of the egg where the rate of metabolism 

 is lower than that of the animal pole op- 

 posite; usually contains yolk material. 



Vein (L. vena, vein). A blood vessel that car- 

 ries blood toward the heart. 



Ven'tral (L. venter, belly). Pertaining to the 

 belly; away from the back. Opposite of 

 dorsal. 



Ven'tri-cle (L. ventriculus, little belly). Any 

 of the small chambers in the anatomy of 

 animals, specifically in the heart, a chamber 

 from which blood is distributed; in the brain, 

 any of the several larger subdi\isions of the 

 central space. 



Ver'mi-form ap-pen'dix (L. vermis, worm; 

 forma, form. L. ad, to; pendo, hang) . A slen- 

 der, tubular pouch projecting from the 

 cecum of the large intestine of some mam- 

 mals. 



Ver'te-bral corumn (L. vertere, to turn. L. 

 columna, column). The series of vertebrae 

 in a vertebrate animal. Backbone. 



Ver'tc-brate (L. vertebratus, jointed). Animals 

 having a vertebral column. 



Ves-tig'i-al (L. vestigium, footstep). A degen- 

 erate structure that was better developed or 

 functional at one time. 



Vil'lus (L. villus, hair). A minute, fingerlike 



