{ { Aril, rarely present. { { { { Ovular coats (one or two usually { { present), the _testa_. { { { { _Funicle_ (stalk of ovule), _raphe_ { { (portion of funicle when bent on { { to the side of ovule), { { _micropyle_, _hilum_ (scar where { _Ripened ovule._ { seed was attached to ovary). { { { { _Remnant of the nucellus_ (central _The seed._ { { part of ovule); sometimes { { nucellus remains as { { _Perisperm_ in some albuminous { seeds. { _Endosperm_, present in albuminous seeds. { { _Embryo_ within surrounded by endosperm when this is { present, or by the remnant of nucellus, and by the { ovular coats which make the _testa_. In many seeds { (example, bean) the endospermis transferred to the { cotyledons which become fleshy(exalbuminous seeds).
=666. Parts of the ovule.=—In fig. 401 are represented three different kinds of ovules, which depend on the position of the ovule with reference to its stalk. The funicle is the stalk of the ovule, the hilum is the point of attachment of the ovule with the ovary, the raphe is the part of the funicle in contact with the ovule in inverted ovules, the chalaza is the portion of the ovule where the nucellus and the integuments merge at the base of the ovule, and the micropyle is the opening at the apex of the ovule where the coats do not meet.
_A_, represents a straight (orthotropous) ovule of polygonum; _B_, the inverted (anatropous) ovule of the lily; and _C_, the right-angled (campylotropous) ovule of the bean. _f_, funicle; _c_, chalaza; _k_, nucellus; _ai_, outer integument; _ii_, inner integument; _m_, micropyle; _em_, embryo sac.]
=667. The stamens and pistils are not the sexual organs.=—Before the sexual organs and sexual processes in plants were properly understood it was customary for botanists to speak of the stamens and pistils of flowering plants as the sexual organs. Some of the early botanists, a century ago, found that in many plants the seed would not form unless first the pollen from the stamens came to be deposited on the stigma of the pistil. A little further study showed that the pollen germinated on the stigma and formed a tube which made its way down through the pistil and into the ovule.
This process, including the deposition of the pollen on the stigma, was supposed to be fertilization, the stamen was looked on as the male sexual organ, and the pistil as the female sexual organ. We have found out, however, by further study, and especially by a comparison of the flowering plants and the lower plants, that the stamens and pistils are not the sexual organs of the flower.