422 BIOLOGY 



telophase. The last stage of karyokinesis, 87. 



tendons. Bands of connective tissue binding muscles to bones, 185. 



tentacles. Appendages from an animal, usually motile, and serving as 



sensory and prehensile organs, 141. 

 testis. See spermary. 

 thalamencephalon. The small section of the brain behind the cerebrum, 



with the pineal gland on top of it, 193. 

 thallophyte (Gr. thallos = a shoot + phyton = a plant). A plant that 



does not show differentiation into root, stem, and leaf, 375. 

 thallus (Gr. thallos = a shoot). A flat leaf or branch, 

 thermotropism (Gr. thermos = heat + trope = a turning) . Reaction to 



temperature, 57. 

 thigmotropism (Gr. thigma = touch + trope = a turning) . Reaction to 



mechanical stimulation, 57. 

 thoracic duct. The large lymph duct in mammals, carrying lymph from 



the lower parts of the body to the veins in the neck, 209. 

 thymus. A ductless gland in the neck, especially prominent in the young, 

 thyroid gland. A ductless gland in the neck below the larynx, 

 tibia, 182. 



tissue (Lat. texere = to weave). A collection of similar cells in a multi- 

 cellular animal, 27, 95. 

 tongue, 185. 



tonsils. Two ductless glands in the back part of the mouth, 

 touch, 198. 



touch corpuscles. End organs of touch. 

 trachea (Gr. trachea = windpipe). -The air passage from the lungs; the 



windpipe, 209. 

 tracheids. The thick-walled wood cells with tapering ends, found in fibro- 



vascular bundles, 105. 

 transformation of energy, 296. 



transpiration. The evaporation of water through the leaves, 

 transverse processes (Lat. trans = across + vertere = to turn). Lateral 



projections from the vertebrae, 177. 

 Trichina, 231. 

 trichocysts, 61. 



tricuspid valve. The valve between the right auricle and ventricle, 

 trigeminal. The fifth cerebral nerve, supplying the sides of the head with 



sensations, 194. 



trypsin. A ferment found in pancreatic juice, digesting proteids. 

 tubercles. Knob-like growths, usually indications of disease, 

 tuberculosis, 231, 232. 

 turgor. The pressure of liquids within the cells of plants. 



