APPENDIX F
GLOSSARY
Acquired Character, a modification of a germinal trait after cell fusion. It is difficult to draw a line between characters that are acquired and those that are inborn. The idea involved is as follows: in a standard environment, a given factor in the germ-plasm will develop into a trait which varies not very widely about a certain mean. The mean of this trait is taken as representing the germinal trait in its typical condition. But if the environment be not standard, if it be considerably changed, the trait will develop a variation far from the mean of that trait in the species. Thus an American, whose skin in the standard environment of the United States would be blonde, may under the environment of Cuba develop into a brunette. Such a wide variation from the mean thus caused is called an acquired character; it is usually impressed on the organism after the germinal trait has reached a full, typical development.
Allelomorph (one another form), one of a pair of factors which are alternative to each other in Mendelian inheritance. Instead of a single pair, there may be a group of "multiple allelomorphs," each member being alternative to every other member of the group.
Allelomorphism, a relation between two or more factors, such that two which are present in one zygote do not both enter into the same gamete, but are separated into sister gametes.
Biometry (life measure), the study of biology by statistical methods.
Brachydactyly (short-finger), a condition in which the bones, particularly of the fingers and toes, fail to grow to their normal length. In well-marked cases one of these is a reduction from three phalanges or joints to two.
Character (a contraction of "characteristic"), a term which is used, often rather vaguely, to designate any function, feature, or organ of the body or mind.
Chromosome (color body, so called from its affinity for certain stains), a body of peculiar protoplasm, in the nucleus of the cell. Each species has its own characteristic number; the cells of the human body contain 24 chromosomes each.
Congenital (with birth), present at birth. The term fails to distinguish between traits which are actually inherited, and modifications acquired during prenatal life. In the interest of clear thinking its use should be avoided so far as possible.