. Elementary botany . the integuments increase in extent and harden as the seed is formed. 461. Perisperm. — In most plants the nuce llus is all consumed in the devel- opment of the endosperm, so that only minute frag- ments of disorganized cell walls remain next the in- ner integument. In some plants, however, (the water- lily family, the pepper „ ^ig. 308. J J 1 rr Diagrammatic section of ovary and ovule at time family, etc.,) a portion of of fertilization in angiosperm /, funicle of ovule; J '/ x Hi nucellus; ;;/, micropyle; o, antipodal cells or the nucellus remains in- embryo sac ; *, end

. Elementary botany . the integuments increase in extent and harden as the seed is formed. 461. Perisperm. — In most plants the nuce llus is all consumed in the devel- opment of the endosperm, so that only minute frag- ments of disorganized cell walls remain next the in- ner integument. In some plants, however, (the water- lily family, the pepper „ ^ig. 308. J J 1 rr Diagrammatic section of ovary and ovule at time family, etc.,) a portion of of fertilization in angiosperm /, funicle of ovule; J '/ x Hi nucellus; ;;/, micropyle; o, antipodal cells or the nucellus remains in- embryo sac ; *, end

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. Elementary botany . the integuments increase in extent and harden as the seed is formed. 461. Perisperm. — In most plants the nuce llus is all consumed in the devel- opment of the endosperm, so that only minute frag- ments of disorganized cell walls remain next the in- ner integument. In some plants, however, (the water- lily family, the pepper „ ^ig. 308. J J 1 rr Diagrammatic section of ovary and ovule at time family, etc.,) a portion of of fertilization in angiosperm /, funicle of ovule; J '/ x Hi nucellus; ;;/, micropyle; o, antipodal cells or the nucellus remains in- embryo sac ; *, endosperm nucleus ; X-, egg cell and synergids ; ai, outer integument of ovule ; //, inner tact in the mature Seed, integument The track of the pollen tube is shown down through the style, walls of the ovary to the In Such Seeds the remain- micropylar end of the embryo sac. ing portion of the nucellus is the perisperm. 462. Presence or absence of endosperm in the seed.—In many of the angiosperms all of the endosperm is consumed by the embryo during its growth in the formation of the seed. This is the case in the rose family, crucifers, composites, willows, oaks, legumes, etc., as in the acorn, the bean, pea and others. In some, as in the bean, a large part of the nutrient substance pass-