Knight — 56 — Dictionary 



Feral. — Wild (i.e. not cultivated). 



Fertile. — Capable of producing viable seeds, or offspring. 



Fertilization. — The fusion of two gametes, male and female, 

 to form a zygote. 



Fertilization Cone. — A small conical projection which is pro- 

 truded from the surface of certain eggs at the point of contact 

 with the sperm. 



Fertilization Membrane. — A membrane which grows out- 

 ward from the point of contact of egg and sperm and which 

 rapidly covers the whole egg surface. 



Fertilizin. — A soluble substance produced by the egg and 

 assumed to play an essential part in fertilization as a chemical 

 link between egg and sperm (Lillie; Wilson). 



Fetus. — Foetus, q.v. 



Filament. — The stalk on which an anther is borne. 



Filial Generations. — F^, F2, F3 etc., q.v. 



Filial Regression. — The tendency of offspring of outstand- 

 ing parentage to revert to average for species (Henderson). 



Finalism. — The concept that the world (or the universe) has 

 a definite purposive goal. 



First Division. — The earlier of the two meiotic divisions, 

 often called the heterotypic or reduction division. 



Fission. — (i) Asexual division of a unicellular organism into 

 two. (ii) Division of a nucleus without, apparently, any 

 mechanism for ensuring an equal distribution of homologous 

 chromosomes. 



Fixation. — The process of killing and coagulating a cell by 

 means of some chemical or physical agency. 



Fixed. — Of a character, race, variety, etc. : pure-breeding, 

 homozygous. 



Floret. — A small flower, usually in a clustered inflorescence. 



Foetalization. — The prolongation into post-natal or adult 

 life of foetal characters of remote ancestors. 



Foetus. — An embryo in utero or before hatching from an 



egg- 



Folic Acid. — One of the components of the vitamin B^ com- 

 plex. Folic acid prevents anaemia and leucopenia in chicks. 



Follicular Hormone. — A female sex hormone formed by the 

 ovarian follicles. 



Food Pollen. — Pollen formed for the purpose of attracting 

 insects and which is often infertile. 



Fractionation (o£ a gene). — The breaking up of a gene 

 into sub-units during segregation, a process which Bateson 

 believed might occur: "I am satisfied that they (the genes) 



