XX INTRODUCTION. 



ovoid, when egg-sliaped, with the broad end downwards, obovoid, if the 

 broad end is upwards ; these terms corresponding to ovate and obovate shapes 

 in flat surfaces. 



globular or spherical, when corresponding to orbicular in a flat surface. 

 Mound applies to both. 



turbinate, when shaped like a top. 



conical, when tapering upwards ; obconical, when tapering downwards, if 

 in both eases a transverse section shows a circle. 



pyramidal, when tapering upwards ; obpyramidal, w T hen tapering down- 

 wards, if in both cases a transverse section shows a triangle or polygon. 



fusiform, or spindle-shaped, when tapering at both ends ; cylindrical, w T hen 

 not tapering at either end, if in both cases the transverse section shows a circle, 

 or sometimes irrespective of the transverse shape. 



terete, when the transverse section is not angular ; trigonous, triquetrous, 

 if the transverse section shows a triangle, irrespective in both cases of longitu- 

 dinal form. 



compressed, when more or less flattened laterally ; depressed, when more 

 or less flattened vertically, or at any rate at the top ; obcompressed (in the 

 achenes of Compositce), when flattened from front to back. 



articulate or jointed, if at any period of their growth (usually when fully 

 formed and approaching their decay, or in the case of fruits when quite ripe) 

 they separate, without tearing, into two or more pieces placed end to end. 

 The joints where they separate are called articulations, each separate piece an 

 article. The name of joint is, in common language, given both to the articu- 

 lation and the article, but more especially to the former. Some modern bota- 

 nists, however, propose to restrict it to the article, giving the name of joining 

 to the articulation. 



didymous, when slightly two-lobed, with rounded obtuse lobes. 



moniliform, or beaded, when much contracted at regular intervals, but not 

 separating spontaneously into articles. 



55. In their consistence Leaves or other organs are 



fleshy, when thick and soft ; succulent is generally used in the same sense, 

 but implies the presence of more juice. 



coriaceous, when firm and dry, or very tough, of the consistence of leather. 



membranous, when thin and not stiff. 



scarious or scariose, when very thin, more or less transparent and not 

 green, yet rather stiff. 



56. The terms applied botanically to the consistence of solids are those in 

 general use in common language. 



57. The mode in which unexpanded leaves are disposed in the leaf-bud is 

 called their vernation or prafoliation ; it varies considerably, and technical 

 terms have been proposed to express some of its varieties, but it has been 

 hitherto rarely noticed in descriptive botany. 



§ 6. Scales, Bracts, and Stipules. 



58. Scales (Squama) are leaves very much reduced in size, usually sessile, 

 seldom green or capable of performing the respiratory functions of leaves. In 

 ©ther words, they are organs resembling leaves in their position on the plant, 

 but differing in size, colour, texture, and functions. They are most frequent 

 on the stock of perennial plants, or at the base of annual branches, especially 

 on the buds of future shoots, when they serve apparently to protect the dormant 

 living germ from the rigour of winter. In the latter case they are usually short, 

 broad, close together, and more or less imbricated, that is, overlapping each 

 Other like the tiles of a roof. It is this arrangement as well as their usual shape 

 that has suggested the name of scales, borrowed from the scales of a fish. Im- 



