APPENDIX A 



GLOSSARY OF TECHNICAL PLANT-BREEDING 

 TERMS 



Allelomorph. One of the pure unit-characters commonly 

 existing singly or in pairs in the germ-cells of mendelian hybrids, 

 and exhibited in varying proportion among the organisms them- 

 selves. Thus an allelomorphic pair of characters comprises the 

 opposed units, one of which comes from each parent in a hybrid. 

 For example, the roundness and wrinkledness found in two varie- 

 ties of peas is an allelomorphic pair. 



Biometry. The application of statistical methods to biological 

 problems. 



Chromosome. A term applied to certain minute bodies, in 

 the nuclei of the animal and vegetable cells which appear at 

 definite periods in the division of the cell ; they are constant in 

 number for each species of animal or plant, and are characterized 

 by the fact that they stain very deeply with certain dyes. The 

 chromosomes are supposed to be the bearers of heredity. 



Dominant characters. It often occurs, when two varieties 

 or species are crossed, that the characters of one appear in the 

 first generation hybrid to the exclusion of the other. These 

 are called dominant characters. 



Duplex. The state of inheriting a character that is present 

 in both parents. 



Epistatic. Used to describe a color factor which, in hybrid- 

 ization, covers up or hides other color factors in the first genera- 

 tion hybrid (opposed to hypostatic). 



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