Allantoin — 5 — Alternation of Generations 



Allometry. — The relation between the growth-rate of a part 

 of an individual and the growth-rate of the whole or of another 

 part ; the relationship between growth-rates of different groups, 

 races, genera, etc. 



Allomorphosis. — The relation of parts of organisms at some 

 definite age to wholes or parts also at some definite age but of 

 different groups (races, varieties, species, genera) e.g. tgg 

 size or hatching weight to adult size or weight (Huxley, 

 Needham, & Lerner). 



Allopatric. — Inhabiting distinct separate areas. 



Allopatric Hybridization. — Hybridization between incom- 

 pletely differentiated species, in a border zone, owing to the 

 premature breakdown of a geographic barrier, cf. Sympatric 

 Hybridization. 



Alloplasm. — Highly differentiated protoplasm. 



Alloploidion. — A species derived by allopolyploidy; its in- 

 dividuals, although usually highly variable, are interfertile 

 (Camp & Gilly). 



Allopolyploid. — An organism with more than two sets of 

 chromosomes in its body cells, derived from two or more species 

 (extant or extinct), by hybridization, cj. Autopolyploid. 



Allosomal Inheritance. — The inheritance of characters gov- 

 erned by genes located in an allosome, q.v. 



Allosome. — Any a-typical chromosome (especially if its be- 

 haviour is a-typical), e.g. a sex chromosome, cf. Autosome. 



Allosynapsis. — Allosyndesis, q.v. 



Allosyndesis. — Of polyploids : the association, in pairs, of 

 homologous chromosomes derived from different parents, cj. 

 Autosyndesis. 



Allotetraploid. — An amphidiploid, q.v. 



Allotriploid. — An organism having three sets of chromosomes 

 in the body cells, one set being distinct from the other two. 



Allotropous Flower. — A flower so shaped that its nectar is 

 easy of access to insects. 



Allozygote. — Pearson's term for an organism homozygous 

 for a particular recessive gene, as opposed to protozygote, q.v. 



Alternate Dominance. — A theory of sex-determination which 

 supposed all individuals to be heterozygous for sex but that 

 the male determiners were dominant in male offspring and 

 the female determiners dominant in female offspring. 



Alternation o£ Generations. — An alternation of a sexual 

 with an asexual form, or, cytologically, the alternation of a 

 haploid with a diploid stage. 



