ARRANGEMENT. --3 



a. The vernation of the leaf is exhibited in a most interesting manner, by 

 making, with a keen instrument, a cross-section of tlie bud in its swollen state, 

 just before its expansion; or it may be well observed hiy removing the scales. 



217. The foiTOS of vernation are mostly similar to those of ajstivation (108), 

 and are expressed by similar terms. Some of the principal are the foUowino- : 



1. Equitmif, overlapping each 

 other in a parallel manner, with- 

 out any involution, as in the 

 leaves of the Iris. 



2. OiyoZM^c, one of the margins 

 of each leaf interior and the 

 other exterior to the margin of 

 the leaf opposite. Ex. sage} 



FIG. 27. — Forrasofvernaiion. The numbers agree 3. Involute, having the edge.? 

 with Ihe correspoiuling paragraphs. rolled inwards. Ex. apple, violct. 





4. Iievolute,^]\e margins rolled outwards or backwards. Ex. willow, rosemary 



5. Convolut^^ ihe leaf wholly rolled up from one of its sides, as in the chcn-y. 

 C. Plaited, each leaf folded like a fan. Ex. vine, birch. 



7. Circinate, when rolled downwards from the apex. Ex. stmdew, fern. 



§ 3. APwRANGEMENT. 



218. In regard to their insertion upon the axis, the an-ange 

 ment of the young leaves in the bud-'is nearly or quite circular, 

 but by the development of the axis, tliis ai-rangement is modi- 

 fied in various ways, and the leaves are then said to be 



1. Scattered, or nregular, as m. the potatoe. 



2. Alternate, one above the other, on opposite sides. Ex. pea. 



3. Op2Jositc,\-\yo against each other at the same node (172). 



Ex. Hydrangia.\ 



4. Vcrticillate, or whorled, more than two m. a circle at each 



node. Ex. meadow lily. 



5. Fasciculate, ox tufted, in crowded whorls, or spires. Ex. 



Callitriche. '. 



219 Wc have formerly sho^vn how some of these modes of arrangement may 

 be reconciled with the spiral (174, o), and we here add, that, in general, when the 

 leaves are said to be scattered or alternate, they will be found, by the attentive 

 observer, to be strictly, though perhaps iiTcgularly, spu'al ; — always so in the 

 annual shoot. 



a. Thus in the iiotato-vine, above cited, or in tlie house-leek, poplar, &c., if we 

 commence at the lower leaf, and draw a line to the next above it, thence to the 

 next and so on to the sixth leaf, we shall have gone just once around the Etcm, 

 8 



