GLOSSARY 407 



Tadpole {tad' pole). The larva of a frog, toad, or certain other animals. 



Tail (tale). A slender posterior appendage. In a spermatozoon, the whip-like 



propelling organ behind the head and mid-piece. 

 Tamarack (tain' arak). The American larch, a bog-inhabiting tree. 

 Tamiasciurus (ta' mi a si u' rus) . The subgenus of the genus Sciurus including the red 



squirrels. Sciurus (Tamiasciurus) hudsonicus loquax {hud son' i kus lo' kwaks) , 



the southern Hudsonian red squirrel. 

 Tarsal {tar' sal). One of a number of bones in the ankle of most vertebrate animals. 

 Tarso -metatarsus {tar' so met' a tar' sus) . A compound bone in the leg of a bird, 



formed of several of the metatarsals and tarsals. 

 Taxis {laks' is). An orientation of an organism with reference to a stimulus. 

 Taxonomy {taks on' o mi). The science of the classification of animals or plants. 

 Teleostomi {te' le os' to mi) . A subclass of Pisces comprising the true fishes. They 



have a skeleton partly or wholly of bone, and respire by means of gills. 

 Telolecithal {teV o les' i thai). Having the yolk massed toward one side; said of eggs 



in which the yolk is most abundant in the vegetative half. 

 Telophase {teV ofaze). The final phase of mitotic cell division, in which the nuclei 



are reconstructed. 

 Tentacle {ten' iak'l). One of a number of arm-hke projections from hydroids, 



Bryozoa, Nautilus, and other animals. Also one of certain elongated individuals 



of a siphonophore colony. 

 Tentaculate {ten tak' u late). Bearing tentacles. 

 Terrigenous {ter rij' enus). Derived from the land; as applied to lake bottoms, 



composed of material washed in from the land, as distinguished from material of 



organic origin. 

 Tertiary {ter' shi a ri). The earlier of two divisions of Cenozoic time. 

 Test {test). A hard outer covering, capsule, or shell; as of a sea-urchin. 

 Testis {tes' tis). The organ in which male germ cells are lodged and developed. 

 Testudinata {tes tu' di na' ta). An order of reptiles, comprising the turtles. 

 Testudinidse {tes' tu din' % dee) . A family of turtles. 

 Tetrabranchiate {tef ra hrang' ki ate). Having four gills; appUed to a division of the 



Cephalopoda. 

 Tetrad {tef rad) . A quadruple body formed, during the growth period in the matura- 

 tion of germ cells, from the union of two chromosomes which at the same time 



divide in two. 

 Tetraxon {tetraks' on). Having four axes radiating from a common center; said of 



certain sponge spicules. 

 Thales {tha' leez). A Greek philosopher and astronomer who lived about 640-546 b.c. 

 Thamnophis {tham' no fis) . A genus of garter snakes. T. butleri {but'leri); T. 



proximus {proks' i mus); T. sackeni {sak' en i); T. sauritus {saw ri' tus). 

 Thermotaxis {ther' mo taks' is). A response to temperature. 



Thermotropism {thermof ro piz'm). The response of an organism to temperature. 

 Thigmotaxis {thig' mo taks' is) . An orientation of an organism with reference to a 



contact stimulus. 

 Thigmotropism {thig mot' ro piz'm). The response of an organism to the stimulus of 



contact. 

 Thoracic {tho ras' ik). Pertaining to the thorax or chest. 



