OP THE LEAVES. 469 



thus altered, but the following species appear to be 

 particularly subject to this change : jEscuIus Hijypocas- 

 tanum, Digitalis purpurea^ Moms alba, Fagus silvatica 

 contracta (hort.), Godiceum variegatum var. erosum 

 (hort.), Brotissonettia papyrifera, Scolopendrium vulgar e, 

 &c. 



Frequently this irregular diminution in proportion 

 is coexistent with an unusual degree of cleavage or 

 laciniation of the margin, as in Acer platanoides lacinia- 

 tum, Tilia asplenifolia, Alnus imperialis (hort.), Fagus 

 silvatica var. (hort.), &c. 



In the case of what are sometimes termed interrupted 

 leaves, the laminar portions of the leaf are here and 

 there deficient on both sides of the midrib, leaving 

 small portions of the latter, as it were, denuded and 

 connecting the segments of the laminae one with the 

 other. This has been observed amongst other plants 

 in Veronica latifolia, Brmissonettia papyrifera, Godiceum 

 variegatum var. interruptum (hort.), Scolopendrium vul- 

 gare, kc} (See p. 328.) 



In some of the leaves which have been already re- 

 ferred to in illustration of the inordinate growth of 

 the cellular portions, the increased development of 

 parenchyma is associated with a contracted state of 

 the midrib and its branches, producing a puckered 

 appearance of the leaf, an exaggerated degree of that 

 change which produces what are termed *' folia bul- 

 lata." In illustration may be cited various species of 

 Mentha, Ferilla, Goleus, Fagus silvatica crispa, Gytisus, 

 Lahwnum var., and other forms, cultivated in gardens 

 for their singularity. 



Entire absence of the stalk of the leaf occurs nor- 

 mally in sessile leaves ; on the other hand the blade of 

 the leaf is only occasionally developed in the phyllodi- 

 neous Acacias, in some species of Oxalis, Indigoferay 

 Lebeckia, Ranunculus, Bupleurum, &c. 



' On the subject of this paragraph the reader may consult A. Braun, 

 " Ueber abnorme Blattbildung. &c., in * Verhandl.,' d. 35, * Naturfor- 

 schcrversammlung ;' Jaeger, 'Floi-a,' 1850, p. 481, tab. 4, Digitalis. 



