The terms **trinomial**, quadrinomial, multinomial, &c., are applied to expressions composed similarly of three, four or many quantities.

A multinomial consisting of two or of three terms is a binomial or a **trinomial**.

He introduced the terms multinomial, **trinomial**, quadrinomial, &c., and considerably simplified the notation for decimals.

- It is obvious that the Linnaean binomial terminology and its subsequent **trinomial** refinement for species, sub-species, and varieties was adapted to express the differences between animals as they exist to-day, distributed contemporaneously over the surface of the earth, and that it is wholly inadapted to express either the minute gradations of successive generic series or the branchings of a genetically connected chain of life.