Note 1 — Front matter

The two fundamental principles usually termed Mendelian are: (1) that of alternative inheritance, viz., that of two corresponding but contrasted pairs of characters of the parents, only one appears in the offspring. This is known as the dominant character; the character not appearing is the recessive character. (2) The law of segregation of characters, according to which both dominant and recessive characters reappear pure in 25% each of the offspring of hybrids.—Ed.