A GRAIN OF BARLEY. 93 
give you a short sketch of its subsequent development; but 
in order to render my remarks more intelligible to those who 
have not any previous knowledge of structural botany, I will 
first of all call your attention to a diagram which represents a 
longitudinal section through a very simple flower. 
This does not represent any one particular flower, but 
expresses in a diagrammatic form the general features of most 
of the ordinary hermaphrodite flowers. 
The floral envelopes, the calyx and the corolla, are supposed 
to be cut away, leaving only those parts of the flower which 
are essential to the reproduction of the plant. 
The two filaments, ¢,¢, which stand up on either side are 
the stamens, carrying at their extremities the anthers, a,b, with 
their pollen-sacs filled with pollen-grains. The central portion 
is the carfel, of which the essential parts are the ovary, f, 
the style, g, and the stigma, hk. The function of the stigma, 
whose surface is generally viscid, is to receive the grains of 
pollen from the opening anthers. These grains of pollen may 
either be derived from the anthers of the same flower, or from 
the anthers of another flower of the same species, either by 
the agency of the wind or of insects. 
The ovule, 0, which is contained in the ovary, is the 
immature seed, and is connected with the base of the carpel 
by an attachment known as the /fumicle, n. The point of 
attachment of the ovule to the funicle is the 47/um, and this, 
no matter what its position may be, is considered the base of 
the ovule, the opposite extremity being its apex. In the 
early stages of development the ovule forms a direct con- 
tinuation of the line of the funiculus, but in many plants it 
ultimately becomes bent back, as shown in the Figure. Such 
an ovule is said to be anatropous. 
The ovule, which is enclosed by the ovary, consists of a 
central cellular portion, the zwucleus, s, surrounded by two 
somewhat thick integuments, an outer, 4, and an inner, g. 
These grow from the base of the nucleus, which they com- 
pletely envelop, except at the apex, where both integuments 
