138 GLOSSARY 



members of an aUeloniorphic pair of characters, the member 

 of the pair which does not appear in the offspring is called 

 recessive. 



Reversion. A 'throw-back* to a previous ancestor, or to the 

 type of the species, when varieties are crossed. 



Segregation. In Mendelian inheritance, the separation of the 

 two characters of an allelomorphic pair, in a heterozygote, 

 into distinct germ-cells, i.e. the formation of gametes each 

 bearing one character of a pair, by an individual which 

 contains both members. 



Self -fertilisation . The fertilisation of a female gamete by a male 

 gamete produced froin the same individual. The process in 

 plants is spoken of shortly as selfing. 



Spermatozoon. See Germ-cell. 



Style. The part of a flower which receives the pollen, and con- 

 ducts the male germ-cell to the egg-cell. 



Telegony. The supposed influence of a former sire upon young- 

 born to a later sire by the same mother. 



Type. The normal form of a species, which is regarded as 

 typical. 



Variation, Variability. The differing among themselves of 

 individuals of the same species. When the extreme forms 

 are connected by a complete series of intermediates, the 

 variation is Continuous-, when distinct forms occur, not 

 connected by intermediates, it is Discontinuous. 



Zygote, An individual produced by the union of two gametes. 



