mi i "i «.',]•, 



CLASS V. DICTYOGENS. 



There i- among the plants referred !>\ Jussieu to 

 consequent!; by later Botanists i~> Endogens, a -mull uumlx 

 whose Foliage and habit of growth are bo very peculiar, • 

 reference of them to Bndogens i- wholly dependent upon i 

 in tin- Btructore of the embryo. Tin'} have a broad m I 

 which n-iiall v disarticuIateG with tin- stem, ami in Borne • 



■I Bowers an- very nearly the Bame a- those of Buch pli 

 mum, among Exogens. For these reasons 1 have endeavoured 1 

 thej ought to be regarded a- a transition class partaki I the 



nature of Endogens ami also of that of Exogens. And il 

 merely the foliage, the distinction seems admissible, for no Kin! 

 Buch a character except a few Arads, otherwise widely different. 

 Dearest approach to this Btructure, with which 1 am acquainted, i 

 Lilium giganteum, hut the leaves of that plant have a Hat folia* tiole 



ami <1«> not disarticulate. The broad-leaved Amaryllids hke Griffii 

 Eurycles, &c., are totally different ; their 1. aves not only havii ticu- 



lation \\ i t h the Btem, but having no reticulations between the ribs, fu 

 than what arises from the anastomosing of the fine paralli 

 veins which connect them. 



It is not, however, in the 1 lone that a distinction is found : 



Endogens and Dictyogens. [f the annual branch* 

 mined, there is nothing indeed in their internal -tincture at variance v hi. 

 of a stem of Asp tartly Endogenous; but in the 



of the whole genus (take the Sarsaparilla of the shops for ii the 



wood is disposed in a compact circle, below a cortical integument, 



surrounding a true pith ; in that of Smilax aspera the w Ij m 



disposed in the form of a cylinder, inclosing a centn cellular 



and the vessels of the cylinder have an evident tendency to an 

 in lines forming rayB from the centre. In Dioscorea slata t ; 

 forme. i of eight fibrovasculai placed in pairs, with their I 



ing the hark, surrounding a central pith and having wide medullar; 

 between them ; in fact, when th< >f this plant are in 



the eight fibrovascular wedges may be pulled asunder, like tl 

 wort or a Klenisperm. In the curious Testudin 

 Btructure of the Btem is of nearly the Bame kind ; 

 fibrovascular tissue form a circle surrounding a pit] . 

 medullary processes, Lapageria and Philesia ha> 

 below their hark, and a central pith in which thi 

 hundles ot' Kndogens arc disposed ; a tendencj to i 

 in Smilax. It therefore seems that the pcculiariti* 

 plants are accompanied by oth< illy rem.. 



the stem ; indeed 1 do not Bee why th. - 



I a title to be regarded E 

 indeed has remarked that he I 

 the roots o\' Bndogens to hav< a simple 

 bundles ; and this seems to be som< I 



