MS 



in tin* form of medullar) proa md the 



■ call their cortical integument, is ii'>t parallel irith I 

 spontaneously separable from it. The onhj 

 stem of Bzogens corresponds with that of ] 

 Wendy matter is connected with the leaves ; and in botL 

 i- the foundation of the whole structure. N 

 made bj some modern physiologists to ideutif) the two, and I 

 the one is verj little different from tin- other. 



It is not, however, to !"■ supposed that themanni 

 is in all cases exactly ulna has been thus d< 

 <»n the contrary, a great variety of modifications has been found 

 dependent in part upon an i development of cellul 



part upon the formation of angles, ' sinuosities, upon tbi 



centric rings of wood for which a great homogeneity of struct i 

 tuted, and upon the production of irregular zom llular n 



bling dark, between the zones of wood. ' this kind h 



tlic attention <>f most modern botanists. Several have been d d my 



Introduction to Botany, in the Penny Cyclopaedia, art. E I \>\ 



Decoisne, A.drien de Ju Schultz, Gaudichaud and Schleiden ; but 



have not been applied successfully to systematical purposes. In a - 

 a possible plan of extending the classes of plants at the ex] 

 [Bot.Reg. 1839. M ■■-. p. 7''". I h&\ . ested the formation i 



ailed Bomogens, to which it has been proposed to unite Births 

 Nepentha, Lardizabalods, Kfenisperms, Peppers, and several othe 

 The character upon which reUance was placed was the remarkabl 

 dt' the wood of these plants, which never have mure than on 

 matter, t<> what< they may have arrived. M. i' 



shown i M> - /. I, that although this ;• 



extremely -n iking in some cases, as for example, in 

 that it i- not constant in oven the same Ord« r, A. Clematitis having 

 zones : ami that in Ifenispermads, while there i- 

 the ordinary structure of Bxogens, except Aristolocl 

 the liber, the wood is regularly zoned in many in-: 

 dotted vessels are wanting. 



Nevertheless, although from the very imperfect Btate 

 concerning the tine structure of the stems of plants, I am unabl 

 retaining this division, such reasons a- would he satisfactory, y< I I tl 

 lie recognised hereafter, either wholly or in part : 



the time will come when the internal BtTUCture "ft! 



extensively consulted than it now i-. ami he made th 

 important systematic divisions. Schultz preceded me in 

 paring his Synor t A s f[ 



119, L 832), to which he referred Piperaci 

 N \ ctaginacess, Callitrichacese, Bippuridaces, Myriophj 

 cete, Cycadeacee, Nymph seacese, Nelumbii 

 proposition, like mine, has fallen to the ground 

 he collect- uinler DiphylleiacesB, namely, Dip 

 other-, are in no wise different from the ordin 



gens, yet it must he admitted that Hippurid 



I.'-- resemblance to that plan of organisation. : 

 Schleiden contemplates the possibility of anj 



worthy of notice that he. in his paper" ! 



encesintke Structur s t, translated in th< i- 



