170 natubjLL history of plants. 



wlilcli tlifll'r from the rest of the parenchyma in tlieir much greater 

 consistency, may be isolated from it simply by the pressure of the 

 covering glass of the slide, which disengages without crushing them.' 



" It is impossible to avoid considering these scattered cells, as of 

 the same nature with those which form septa in the pith of the Ma{/- 

 noViece. Thus the whole order is characterized by the identity of 

 tlie structure of these utricles, while their different modes of arrange- 

 ment serve to distinguish the tribes : stony cells, disseminated in 

 SclnzandrecR and Wiiitcrea, collected into diaphragms in Magnoliece. 

 In the rapidly-developed shoots of some Magnolias we have seen 

 these septa reduced to a single stony cell, nearly central, on which all 

 the surrounding cells of the ordinary parenchyma abut by one end, 

 bent, or drawn out in a quite peculiar fashion. 



" ]\Ioreover, the sarmentose stems of the Scldzandrea are dis- 

 tinguished from those of the Winterece by another anatomical cha- 

 racter. Towards the outside of the fibrovascular zone, they present 

 wide vertical tubular cavities, lined with a fine membrane and 

 riddled with very minute perforations ; very often becoming detached 

 from the walls of these cavities in long cylinders which at once 

 collapse." 



The bark of certain Magnoliacea presents peculiarities of structure 

 often related to the use made of this part of the stem in several 

 species we shall enumerate below.- Several years ago Gceppert" 

 pointed out in the bark of Brimys Winteri certain small granula- 

 tions visible even to the naked eye, and remarkable for their con- 

 sistency. They consist of stony cells, dotted, perforated, and often 

 areolate, which correspond pretty closely in structure with the better 

 developed ones which we have described in the medullary paren- 

 chyma.'' When adult, their contents are nearly colourless, or more 



simulating a thick coat of polyliedral starch- pared by Olivee {pp. cit., 3) to that observed 



granules. But these bodies, unattacked by in the stem of certain namamelidacecB ; that 



water, are not dyed blue by tincture of iodine. is — that in the interval between two fibres, we 



In the pericarp c,( M. Yulan Desf., IMillardet find very large lenticular cavities, whose centres 



has recently ascertained that the cells of the abut on the openings of perforations in the walls 



pericarp contain in the thickness of their walls, of each fibre. Here again we have the same fact 



" a real network of canaliculi ramifying in every as in Drimys and the Conifers. 



direction," of which some cnntaln crystals, and ^ g^^]^ ,^j.g |.|,g following aromatic barks: 



the presence of wliich would be an argument in Winter bark, Canella-alba bark, and those of 



favour of the thickening of these cellular walls by Cinnamodendron, the Tulip-tree, and several 



internal deposit {Ann. Sc.Nat., ser. 5,vi. 309). Magnolias used in medicine. 



' Griffith {yotul., iv. 715) has remarked in =* Loc. cit.—EicnLER, he. cit., 138, t. 32. 



the parenchyma of Kadsuru, u structure com- ■• Seep. 169. Heretheir various diameters are 



