Micropyle(redirected from micropyles)
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(1) An opening in the membrane of the eggs of insects, arachnids, some mollusks, fishes, and a number of other animals, through which the spermatozoon penetrates. (2) An opening in the apex of the ovule in higher seed plants, through which the pollen tube penetrates during pollination. The micropyle is formed because the integuments surrounding the ovule are unattached.
the canal in the integument or integuments of a plant through which the ovule is penetrated in gymnosperms by pollen grains and in angiosperms by pollen tubes. The external opening of the micropyle may be observed on the surface of a mature seed in the form of a dark dot.