90 



MANUAL OF BOTANY 



as if ou a saddle (fig. 180), as in the Privet and the leaves of 

 the Iris at their base, they are equitant ; 3rd, when the half of 

 one condiiphoate leaf receives in its fold the half of another folded 

 in the same manner (fig. 181), as in the Sage, the vernation is 

 half-equitant or ohvolute; and 4th, when a convolute leaf 

 encloses another which is rolled up in a like manner (fig. 182), 

 as in the Apricot, the vernation is supervolnte. 



The terms thus used in describing the different kinds of ver- 

 nation are also applied in like manner to the component parts 

 of the flower-bud, that is, so far as the floral envelopes are con- 

 cerned, under the collective name of cestvvationoT prceflfOration. 

 Fig. 176. Fig. 177. Fig. 178. 



Fig. 179. 



Fig. 180. 



Fig. 181. 



Fig. 182. 



Fig. 176. Transverse section of a bud to show the leaves arranged in a val- 



vate manner. Fig. 177. Transverse section of a bud to show imbricate 



vernation. Fig. 178. Transverse section of a bud to show twisted or 



spiral-vernation. Fig. 179. Transverse section of a bud to show indu- 



plicate vernation. Fig. 180. Transverse section of a bud showing equi- 

 tant vernation. Fig. 181. Transverse section of a bud showing obvo'ute 



vernation. Fig. 182. Transverse section of a bud showing supervo]ute 



vernation. 



We shall have therefore to refer to some of them again, together 

 with others, not found in the leaf-bud, when speaking of the 

 flower -bud. 



4. OTHBB MODIFICATIONS OF THE LEAF. 



Besides the kinds of leaf which we have now examined, there 

 occur others which serve various purposes, and are frequently 

 adaptations to special habits of life ; such are spinous leames, 

 leaf-tendrils, and pitchers. Either the whole leaf or part of it 

 may undergo modifications of this kind. We have again the 

 various forms of scaly or cataphyllary leaves, and the leaves 



