Glossary 



Allelomorph, a member of a Mendelian pair of characters. The 

 adjectival form allelomorphic is useful, because by its em- 

 ployment the statement that the character " round " bears 

 that relation to the character " wrinkled " which the two 

 characters of a Mendelian pair bear to one another, can 

 be condensed into the statement that round is allelomorphic 

 to wrinkled. 



Bisexual crosses, according to Prof, de Vries, are those between 

 two individuals each of which bears a particular character, 

 one of them possessing it in a latent and the other in a 

 patent state. Compare with " unisexual." 



Chromosome, a term applied to certain minute bodies, in the 

 kernel or nucleus of the animal and vegetable cell, which 

 appear at definite periods in the division of the cell, are 

 constant in number for each species of animal or plant, 

 and are characterised by the fact that they stain very deeply 

 with certain dyes. The number of chromosomes in a germ 

 cell is half the number of them in a body cell of a given 

 plant or animal. 



Cotyledon, a term applied to the first leaf or leaves of the plant. 

 One group of plants, of which the wheat is an example, is 

 characterised by the possession of only one ; they are called 

 monocotyledons. Another group, of which the pea is an 

 example, has two ; these plants are called dicotyledons. 



DD [See Homozygote). 



DR {See Heterozygote). 



Dominant characters are those borne by the first generation 



275 



