68 



Commercial Gardening 



Fig. 58. Section through 

 the Fruit (Drupe) of a Plum, 

 showing the Epicarp (ep) or 

 Skin, the Sarcocarp (sar) or 

 Flesh, the Endocarp (en) or 

 Stone. In the centre is the 

 solitary Seed or Kernel. 



The inner wall of the ovary becomes bony in the Cherry, Peach, and 

 Plum, while the portion between this and the skin becomes pulpy; the 

 fruit is a drupe (fig. 58). That of the Raspberry and Bramble consists of 

 an aggregation of drupels or small drupes. The Mulberry fruit resembles 

 it, but is made up of a large number of flowers, the perianth of which 

 becomes fleshy, and the fruit is termed a sorosis. 

 This sisterhood of clustered fruits is carried still 

 further in the Pineapple, the flowers, pistils, bracts, 

 and axis forming one pulpy mass. The Fig has a 

 fruit consisting of a whole inflorescence, enclosed in 

 the hollow, pulpy axis, each seed, so-called, being a 

 tiny fruit from the botanist's point of view. 



The circumstances which favour the ripening of 

 fruits under glass are a drier atmosphere, plenty of 

 air, and a higher temperature than usual to secure the 

 chemical changes, whereby harsh and acid juices may 

 become pleasant to the palate, and starch and other 

 reserve matters may be converted into sugar. Black 



grapes require to be shaded by their foliage, and white varieties to be 

 exposed. Cucumbers require a thin shading to prevent the development 

 of too much carbon in them, which means the loss of the green colour. 

 Apples, Pears, Plums, Cherries, Peaches, and Nectarines require full expo- 

 sure to sunlight to change the chlorophyll granules in the skins into red 



and yellow ones. Apples and Pears grown 

 in pots take on the brightest and darkest 

 colours if stood out-of-doors to mature. 



Seeds. When the ovule is fertilized by 

 the union of the nucleus of the pollen tube 

 with the egg cell it becomes a seed. At this 

 stage it consists of three parts: (1) The testa, 

 or skin, made of two layers or coats, and 

 belonging to the mother plant; (2) the endo- 

 sperm, a mass of tissue developed to nourish 

 the embryo; and (3) the embryo or young 

 plant. The endosperm and embryo are new 

 developments, resulting from the act of fer- 

 tilization. As the seed progresses to matu- 

 rity it undergoes great changes, and, in many 

 cases, remarkable developments (figs 59, 60). 

 The testa may remain thin and membra- 

 nous, especially in those cases where it is 

 covered by the walls of the fruit at maturity and after it has fallen away 

 from the mother plant, as in the Buttercup, Clematis, and Chrysanthemum, 

 the fruits of which must not be mistaken for seeds. The testa also remains 

 thin in the Peach and Cherry, where it is protected by the bony endocarp 

 or stone. It becomes leathery, spongy, or fleshy in different species of Iris, 



Fig. 59. Seeds, showing the Outer Skin 

 or Testa with rugged prominences or pro- 

 jections. The sections show the Seeds cut 

 lengthwise, and show the Embryo with its 

 two Cotyledons, and the Radicle surrounded 

 by the Perisperm. 



1, Hue (Ruta graveolens). 

 below. 



2, Snapdragon 



