Endogenous \En*dog"e*nous\, a.

1. (Bot.) Increasing by internal growth and elongation at the summit, instead of externally, and having no distinction of pith, wood, and bark, as the rattan, the palm, the cornstalk.

2. (Biol.) Originating from within; increasing by internal growth.

Endogenous multiplication (Biol.), a method of cell formation, seen in cells having a cell wall. The nucleus and protoplasm divide into two distinct masses; these in turn become divided and subdivided, each division becoming a new cell, until finally the original cell wall is ruptured and the new cells are liberated (see Segmentation, and Illust. of Cell Division, under Division). This mode of growth is characteristic of many forms of cells, both animal and vegetable.

Source: Webster's Revised Unabridged Dictionary (1913)