- One of two spiral bands of tissue in an egg that connect the yolk to the lining membrane at either end of the shell.
- The region of an ovule that is opposite the micropyle, where the integuments and nucellus are joined.
- In <em>botany</em>, that part of the ovule or seed where the integuments cohere with each other and with the nucleus. It is the true base of the seed, but corresponds to the hilum or scar only in some cases.
- In <em>zoology</em>, one of the two albuminous twisted cords which bind the yolk-bag of an egg to the lining membrane at the two ends of the shell, and keep it near the middle as it floats in the albumen, so that the cicatricula or germinating point is always uppermost, and consequently nearest the source of heat during the process of incubation. Also called <internalXref urlencoded="pullet-sperm">pullet-sperm</internalXref> and <em>treadle.</em>
- Same as <internalXref urlencoded="chalazion">chalazion</internalXref>.
- The place on an ovule, or seed, where its outer coats cohere with each other and the nucleus.
- A spiral band of thickened albuminous substance which exists in the white of the bird's egg, and serves to maintain the yolk in its position; the treadle.
- A <xref>spiral</xref> band which attaches to the <xref>yolk</xref> of an egg, suspending it in the <xref>white</xref>
- The location where the <xref>nucellus</xref> attaches to the <xref>integuments</xref>, opposite the <xref>micropyle</xref>.
- one of two spiral bands of tissue connecting the egg yolk to the enclosing membrane at either end of the shell
- basal part of a plant ovule opposite the micropyle; where integument and nucellus are joined