The early development of the proembryo in monocots follows the same pattern as in the dicots. However, at the time of differentiation in the globular proembryo certain fundamental differences arise. In monocots one half of the terminal cell and its derivatives have retarded growth, whereas the other half grows rapidly to form one cotyledon.
As a result of this asymmetric growth, in later stages the stem tip, which is also derived from the terminal cell, appears to be lateral in position The major differences between the dicot and the monocot embryos arise due to disparity in the number and position of the cells of the terminal quadrant of the proembryo which contribute to the formation of the cotyledonary and epicotyl regions. In the dicotyledons derivatives of the two opposite cells of the terminal quadrant give rise to the two cotyledons. Among the monocotyledons the number of cells of the quadrant that contribute to the cotyledons varies.