micropyle

A minute opening in the ovule of a seed plant through which the pollen tube usually enters.

A pore in the membrane covering the ovum of some animals through which a spermatozoon can enter.

In zoology: In certain sporozoans, a minute opening in the oöcyst through which the microgamete enters to fertilize the macrogamete.

In botany, the orifice or canal in the coats of the ovule leading to the apex of the nucleus, through which the pollen-tube penetrates.

In zoology: The scar or hilum of an ovum at the point of its attachment to the ovary

Any opening in the coverings of an ovum through which spermatozoa may gain access to the interior, or a cluster of minute pores on the surface of an egg through which fertilization is effected. On the eggs of lepidopterous insects these pores often form a rosette at one end.

An opening in the membranes surrounding the ovum, by which nutrition is assisted and the entrance of the spermatozoa permitted.

An opening in the outer coat of a seed, through which the fecundating pollen enters the ovule.

In seed-bearing plants, a small opening in the integuments of the ovule through which sperm are able to access the ovum.

minute opening in the wall of an ovule through which the pollen tube enters