T-chromosome. — A chromosome which in addition to the 

 usual centromere, has a secondary centre of attraction towards 

 the pole. Where this secondary centre is located at the end 

 of a chromosome, the term T-end is used. These secondary 

 centres do not appear to be translocated centromeres (cf. 



OsTERGREN and Prakken). 

 T-effect. — Any phenomenon associated specifically with the 



secondary attraction centres found in T-chromosomes, q.v. 



T-bivalents, T-rods, T-trivalents refer to bivalents, rods, etc. 



showing the T-effect. 

 T-end. — See under T-chromosome. 

 Tachyauxesis. — Ontogenetic heterauxesis in which the growth 



of the part is faster than that of the body as a whole. 

 Tachygenesis. — An abbreviated, quickened development in 



which one or more of the embryonic or larval developmental 



stages are omitted. 

 Tachytelic. — Evolving much faster than the modal rate. 



cf. Horotelic and Bradytelic. 

 Tandem Satellites. — Two short segments of chromosome 



separated from each other by a constriction and from the main 



body of the chromosome by a second constriction. 

 Tassel. — The staminate inflorescence of maize. 

 Telegony. — The erroneously supposed influence of one mate 



of a female on her progeny by other subsequent mates. 

 Teleianthous. — Of a flower: complete, hermaphrodite. 

 Teleology. — The doctrine that evolution is purposive with 



a definite goal and that biological structures can be interpreted 



in terms of the purpose they serve. Adj. Teleological. 

 Teleosis. — Evolution by teleology, q.v. Adj. Telle. 

 Telianthous. — Teleianthous, q.v. 

 Telocentric Chromosome. — A chromosome with a terminal 



centromere. 

 Telekinesis. — Telophase, q.v. 

 Telolecithal. — Of an egg: having the bulk of the yolk in 



one hemisphere. 



