. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. Section of half-ripe fruit of the same, 50 diam. The globular dilatation exhibits the following parts: — a, the capsule. Within this, and separating it from the central portion, is a dark space, which corresponds to a cavity of the form of a hollow cylinder ; b, columella ; c, super- ficial layer of central portion; d, remains of archegonium; e, vaginula. (From fig. 164 to 166 from Hofmeister.) ers of cells from the central portion, a cavity of the form of a hollow cylinder, the axis of which coincides with that of the f
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. Section of half-ripe fruit of the same, 50 diam. The globular dilatation exhibits the following parts: — a, the capsule. Within this, and separating it from the central portion, is a dark space, which corresponds to a cavity of the form of a hollow cylinder ; b, columella ; c, super- ficial layer of central portion; d, remains of archegonium; e, vaginula. (From fig. 164 to 166 from Hofmeister.) ers of cells from the central portion, a cavity of the form of a hollow cylinder, the axis of which coincides with that of the fruit. At this stage, the central portion consists of an axile column of large cells, closely invested by a single layer of smaller ones (the columella) ; a superficial layer of cells, about four times as large as those last mentioned ; and Lastly, between the two, a layer of nucleated cells, with granular contents, the primary parent cells of the spores. The development of these last consists in the disappearance of the nu- cleus of each, and the substitution for it of two others ; this being accompanied or fol- lowed by the division of the primordial mem- brane into two new vesicles, each of which encloses a nucleus. A cellulose membrane is now formed at the surface of contact of the two vesicles by which the original cavity is bisected. In the cavity of each of the result- ing nucleated cells, two new ones make their appearance, apparently by contraction of the primordial membrane, either before or inimc1- 239 diately after its division into two halves. On the surface of each half cellulose is secreted, so that the spherical cells which are thus formed possess a delicate cellulose external, and a very distinct inner membrane (primor- dial vesicle.) This last divides into four por- tions (the young spores), each of which becomes invested with a layer of cellulose. The ripe spore has been already described. The capsule now gives way at the line of its insertion on the pedicl
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