APPENDIX I 



Fertilization {continued) 



Double Fertilization (in Angiospernis), the fusion of one male 



gamete with the egg nucleus at the same time as a second male 



gamete fuses with a second female gamete to beget nutritive tissue. 



V. Endosperm. 

 Selective Fertilization, the fusionof germ-cells of different types from 



one or both sexes in combinations having non-random frequencies. 

 Self-Fertilization (Selfing), the fusion of male and female gametes 



from the same haploid or diploid individual. 

 First Division, the first of two divisions of Meiosis, formerly known 



as the heterotypic or reduction division. 

 Fission, division of a one-celled organism into two equal parts in asexual 



reproduction, i.e. by mitosis. 

 Floating, of structual or gene changes for which a Mating Group is 



not uniform. Darlington and Gairdtier 1937. 

 Fragment, i. A new acentric product of chromosome breakage. 



2. A small Supernumerary Chromosome. 

 Freemartin (in cattle), a female which is sterile through having had a 



male twin. 

 Frequency Distribution, the distribution of the frequencies of obser- 

 vation with respect to the classes into which the observations are 



subdivided. 

 Fusion, of chromosomes, v. X-Ray Breakage, Chromosome Fusion. 

 Fusion Nucleus, product of fusion of nuclei in embryo-sac, parent of 



Endosperm. 



Gamete, cell which is specialized for fertilization and does not usually 



develop without it. v. Egg. Strashurger 1877. 

 Unreduced Gamete, having the unreduced or somatic number of 



chromosomes. 

 Gametogenesis, the formation of gametes, including meiosis where 



meiosis immediately precedes the formation of gametes. 

 Gametophyte, an individual of the haploid generation in plants, normally 



producing the gametes. 

 Geminus, Bivalent. 

 Gene, i . Any particle to which the properties of a mendelian factor may 



be attributed. Jo/j(7?/«5CM 1909. 



2. Any particle in a chromosome which is distinguishable from other 

 particles by either crossing-over or mutation. Morgan 1925. 



3. A minimum particle of the chromosome which can be separated 

 from otlicr particles by X-ray breakage. Midler and Prokojicva 1935. 



392 



