AN ENCYCLOPEDIA OF HORTICULTURE. 



537 



Ovary continued. 



which springs from the surface along the midrib of the 

 carpel, enlarging as the seeds ripen. 



FIG. 797. CROSS SECTION OF NEARLY RIPE POD OF ASTRA 

 GALUS, showing Partition growing from near Midrib towards 

 Placentae. 



3. The typical structure of the Ovary is departed 

 from in some plants, in the growth, after the seeds 

 form, of a number of cross partitions ; so that each carpel 

 is made up of a row of divisions, with one seed in 

 each. 



4. The typical situation of the Ovary is, as we have 

 seen, at the tip of the flower-stalk (receptacle), or, at 

 least, nearer to it than are the other parts of the flower 



FIG. 799. CROSS SECTION OF HALF-RIPE CHERRY, showing (p) 

 Pulpy Flesh and (s) Stone. The infolded Edges are clearly 

 seen. 



so that it is concealed. Great use has been made of 

 these differences in Systematic Botany, though absolute 

 reliance on them at times tends to separate nearly allied 

 plants. 



Vol. JLL 



FIG. 798. DIAGRAMS TO ILLUSTRATE MODIFICATIONS OF RE- 

 CEPTACLE, IN LONGITUDINAL SECTIONS OF FLOWERS. In each 

 the parts shown are (r) Receptacle, (*) Sepals, (p) Petals, 

 (*) Stamens, and (c) Carpel, with Ovary, Style, and Stigma. 

 A, Receptacle rounded, with Carpel on tip ; B, Receptacle 

 forms a Saucer-like Disk ; C, Receptacle forms a Cup around, ; 

 but not joined to, Ovary ; D, Receptacle forms a Cup, united to 

 Ovary, which is sunk in it to near the top. In B, C, and D, the 

 Ovary is at the true tip of the Receptacle, and the Sepals, 

 Petals, and Stamens grow out from the edge of the Disk or 

 Cup. 



(see A, Fig. 798). But in many plants the Ovary seems to 

 be more or less completely sunk in the flower-stalk, 

 and to be surrounded by the sepals, petals, and 

 stamens grown together. More careful observation leads 

 to the belief that the receptacle produces, below its 

 apex, a flat ring (see B, Fig. 798) (e.g., in Strawberry), 

 or a cup, which may surround the Ovary (see C, Fig. 

 798), either (e.g.. Cherry) without being united with it, 

 or united to it in part (e.g., Saxifrages), or throughout 

 its whole length (see D, Fig. 798) (e.g., Carrot, Cam- 

 panula, &c.), or even projecting beyond it (e.g., Fuchsia), 



Ovary continued. 



5. Still another mode of departure from the leaf- 

 type shows itself in many Ovaries, as the seeds ripen 

 in them, due to alterations in the texture of their 

 walls. They may become uniformly hard, as in the 

 Acorn, and in the Hazel-nut, or they may become pulpy 

 inside, with a thin, leathery, outer skin, as in the 

 Grape ; or there may be a thin, tough, or hard outer 

 skin, a more or less abundant pulpy middle layer, and 

 a hard inner shell, known as the " stone " in stone-fruits 

 (see Fig. 799). This change is frequent both in simple 

 and in compound or united Ovaries. Such differences in 

 structure are best understood with reference to the 

 modes of distribution of the seeds. 



The ripe fruit is, in most plants, the Ovary merely 

 enlarged, or changed in one or more of the ways indi- 

 cated ; but in some plants the receptacle also enlarges, 

 either into a fleshy head, as in the Strawberry, or the 

 receptacle cup around the Ovary, mentioned above, be- 

 comes fleshy, or, in some form or other, becomes a part 

 of the fruit. The methods of opening, to allow of the 

 escape of the seed, differ greatly in those Ovaries from 

 which the seeds escape when ripe; while one-seeded 

 carpels, or such as have fleshy walls in the ripe condi- 

 tion, usually do not split. The consideration of these 

 differences also belong more to the great subject of the 

 distribution of the seeds than to the subject immediately 

 under notice. 



FIG. 800. OVATE AND OBTUSE LEAP. 



OVATE. The shape of an egg, with the broad end 

 downwards. An Ovate and obtuse leaf is shown at 

 Fig. 800. 



OVIEDA (of Linnaeus). A synonym of Clerodendron 

 (which see). 



OVIEDA (of Sprengel). A synonym of Lapeyrousia 

 (which see). 



OVILIiA. A synonym of Jasione. 



OVOID. A solid with an ovate figure, or resembling 

 an egg. 



OVULE. The name given to that body which 

 develops into the seed, after it has been acted on by 

 the pollen. The Ovules are contained in the Ovary 

 (which see) in all flowering plants, except the Coniferous 

 trees and shrubs, the Cycads, so commonly grown in 

 hot-houses, and a few other mostly tropical plants that 

 form the natural order Gnetaceas. The ovary in almost 

 all Phanerogams is closed, so as to entirely conceal 

 the Ovules; but in a few (see Mignonette) it is open 

 at the top from a very early period. 



The Ovules are attached to the placentae (see Ovary), 

 to which they are fixed by a stalk, or "fnniculus." 

 They are usually very small, and are frequently BO 

 translucent as to allow the microscopic structure to be 

 seen, either without special preparation, or, after laying 

 them for a little time in some fluid (e.g., weak solution 

 of caustic potash), to render them more transparent. 

 Others require more elaborate treatment, and must be 

 cut open before they are fit to be examined; but to 

 enter into details would occupy too much space. The 

 description here must, therefore, be restricted to one of 

 the more simple forms of Ovules, afterwards pointing 

 out in what respecls, chiefly, other forms depart from 

 this type. The Ovule selected for description is one 



3 z 



