226 THE GARDENER. [May 



epidermis or outer covering of the root-fibre. Eich plant, in like 

 manner, has a stem or ascending axis in connection or continuation 

 with the root, the plumule (of which more hereafter), elongated, with 

 leaves and buds on it, sometimes called the air end, or stem fabric of 

 the plant. Where the root ends and the stem begins in the full- 

 grown plant, or in the seed after germination where the radicle 

 ends and the plumule begins, there is situate what is called the neck 

 (collum, in Latin), by gardeners " the collar." It is a guide in plant- 

 ing trees by which the danger may be avoided either of planting too 

 deeply beneath the surface of the soil, and which would therefore be 

 burying part of the stem, or of leaving it too much exposed above 

 the surface, so that the cold of winter might injure and destroy the 

 plant; it is a very sensitive part, and easily injured by the spade or 

 by the foot in the operation of treading. 



Each plant, not a monocotyledonous one, at its earliest growth, 

 will have a simple root, called a tap-root, from which other rootlets, 

 called root-fibres, branch off; the length of this tap-root depends on 

 the physical nature of the soil and its resistance to downward 

 growth. In seedling fruit-trees in their early life it should be cut 

 off to encourage root -fibres, so that they may be more easily 

 transplanted, and be encouraged to produce their roots nearer the 

 surface of the ground, where they will be more accessible to the sun's 

 rays and the gardener's spade than they would be if buried deeply 

 beneath the surface of the soil. 



The following are some of the different forms of roots : the tap-root, 

 as in Carrot ; the fusiform root, as in Radish ; the napiform root, as in 

 Turnip ; the fibrous root, as in grasses, or in plants of simple annual 

 growth ; the tubercular root, or tubercles, as in Orchis; the annulated or 

 ringed root ; the nodulose root (Drop wort), or the fasciculated tuber, as 

 in Dahlia ; and branched roots which become woody, such as in roots 

 of trees and shrubs. 



DOUBLE PRIMULA SINENSIS. 



Although some of the older varieties of double Chinese Primulas, 

 notably the old white, are common enough, they, with few exceptions, 

 seldom receive that amount of attention and good culture that their 

 intrinsic worth merits. In too many greenhouses and other places at 

 the present time, are they to be seen dragging out their existence, 

 sometimes undisturbed in the same pot for years ; while their more 

 showy but really less valuable relations, the single varieties, receive the 

 best of treatment. Even the old double varieties when well grown, 

 not only form very attractive plants, but are also more serviceable 



