= orthotropous, adj. 1.

Designating an ovum of which only a part undergoes cleavage to form the embryo; (also) designating this type of cleavage. Cf. holoblastic, adj.

Of, relating to, or designating a type of meroblastic development in which cleavage takes place at the surface of the ovum. Obsolete. rare.

Of an ovum: Wholly germinal; undergoing total segmentation (as in most mammals). Opposed to meroblastic.

Originally (of an embryo): having the radicle directed towards the hilum; = homotropous, adj. Later (of an ovule): developed in an upright position…

applied to an ovum having food-yolk collected at or near one end (opposed to alecithal and centrolecithal).

= progamic, adj.

Embryology. Designating an ovum of which only a part undergoes cleavage to form the embryo; = meroblastic, adj. Obsolete. rare.

having three ovules.