ORGANS OF EEPEODrCTION. 215 



then afforded by its position on the outside of the latter organ. 

 The Fuchsia, Indian Cress, Columbine, Larkspur, and Monks- 

 hood, may be mentioned as affording examples of a petaloid 

 calyx among Dicotyledonous Plants. In the Monocotyledonous 

 Plants generally, as in the Lily, Iris, Tulip, Crocus, and Squill i^fig. 

 422), as "we have mentioned, the two floral envelopes are usually 

 coloured, and in other respects closely resembling each other, 

 so that "we then use the collective name of perianth to indicate 

 the two whorls taken together. When there is but one whorl of 

 floral envelopes, as in the G-oosefoot (Chenopodmm) {fig. 423), 

 it is customary with some botanists to call that whorl a cal}-x, 

 ■whatever be its colour or other peculiarity. It is so termed in 

 this volume. Other botanists, however, under such circum- 

 stances, call the whorl that is present a perianth, as we have 

 already stated. (See page 208.) 



In their general structure, venation, &c., the sepals resemble 

 true leaA'es, and are covered like them with epidermis, and this 

 is frequently furnished on the lower and outer surface with sto- 

 mata, and also occasionally with hairs, glands, and other append- 

 ages. From the duration of the sepals being usually more 

 transitory than that of true leaves, the veins which form their 

 skeleton chiefly consist of true spiral vessels, which are arranged 

 like those of the leaves in the two classes of plants — that is, reti- 

 culated in Dicotyledons, and parallel in Monocotyledons. 



The sepals also exhibit various characters as regards their 

 outline, apex, &c., although they are by no means so liable to 

 variations in these particulars as the true leaves. The terms 

 used in defining these various modifications are applied in the 

 same sense as with leaves. 



Sepals are almost without exception destitute of a stalk, or, 

 in other words, they are sessile upon the thalamus. They are 

 also generally entire at their margins, although exceptions to this 

 character occasionally occur : thus, in the Pseony and Eose {figs. 

 437 and 460, cf), the sepals are divided at their margins ; in many 

 species of Dock {Bumcx) they are toothed {fig. 438, «'); in 

 ChamcBlaucium 'plumosum each of the sepals is divided into five 

 deep lobes ; and in Passiflora foetida, the sepals are first pinnati- 

 sected, and then each segment pinnatifid. In their direction, the 

 sepals are either erect or turned upwards ; connivent or turned 

 inwards ; divergent ov patulous, when they spread outwards ; or 

 reflcxed, when their extremities are turned downwards. 



The calyx may either consist of two or more separate parts 

 or sepals, as in the Poppy, Buttercup, Wallflower, Strawberry, 

 {fig. 439); or these parts may be more or less united into one 

 body {figs. 441-445), as in the Fuchsia, Melon, and Tobacco. 

 In the former case, the calyx is termed folysepalous, dialt/sepa- 

 lous, ox polyphyllous, the term phylla being here used instead of 

 sepal. When the sepals are more or less united into one body 



