i879-] THE GARDENER'S PRIMER. 511 



by the protrusion of the pollen tube (in Orchids this tube may 

 easily be seen and traced to the ovule), which, passing through the 

 stigma and style (often cylindrical), fertilises and energises the ovule 

 in the ovary at the base of the pistil. These ovules are regarded as 

 buds formed in the axils of carpellary leaves, and are the seeds, some- 

 times called seed-buds. The structure of the style (not always present), 

 and the divisions of the ovary into dissepiments, all point to the 

 fitting together of the edges or sides of so many carpellary leaves — 

 the number of which made use of may sometimes be ascertained by 

 counting the dissepiments of the ovary. The fruit, strictly speaking, 

 is the matured ovary of the pistil (in its fruit state metamorphosed 

 into the pericarp or seed-vessel), the result of the fertilisation of the 

 pistil of one flower produced by the interaction of stamens. To un- 

 derstand the complicated question aright the gardener should study 

 the flower while in blossom, and watch the silent changes and modi- 

 fications of the ovary, whether for protection of the seeds or for 

 food. One modification is into the pericarp, which consists of three 

 layers, very clearly seen in the Peach — namely, the skin or epicarp, 

 the fleshy pulpy layer called the mesocarp, and the stone, called the 

 endocarp or covering of the kernel. It is to the adherence of the 

 mesocarp to the endocarp that some varieties of Peaches have ob- 

 tained the name of clingstone, and to the freeness with which others 

 separate from the endocarp, the name of freestone owes its origin. 

 Other modifications are the pulpy disk or receptacle of the Strawberry, 

 the calyx and ovary and receptacle of the Apple, the developed 

 pulpy state of the placenta of the Gooseberry and Grape, the bracts 

 and floral envelopes of the Pine-apple, the peduncle of the Fig, and 

 the calyx in the Rose. It will soon occur to him that he should 'find 

 some trace of the style of the pistil, which he may often do (except in 

 Cycadeae and Coniferse) even in a grain of wheat, which is a fruit and 

 not a seed, and that our simple definition of fruit is not always sufficient. 

 Several systems of classification of fruits are in use, none of them alto- 

 gether satisfactory. We shall confine our remarks to simple, and mul- 

 tiple or compound, fruits. Simple fruits are formed either by the pistil 

 of one flower out of a single carpel or carpellary leaf, instances of which 

 are, — the follicle (Prcony) — the legume (Pea) — the achaenium (plural 

 achseaia) or achene, a closed fruit, dry, small nut, with the pericarp 

 as in Sunflower — the caryopsis as in Wheat — the drupe (Peach) ; or 

 by the pistil of one flower out of several free carpels or carpellary 

 leaves, instances of which are, — several dry achenes on a dry elevated 

 receptacle, as in Ranunculus — an etserio, that is, many fleshy drupes 

 together, as in Rubus — dry achenes seated on a fleshy receptacle, as 

 in Strawberry ; or by the pistil of one flower formed out of several 



