324 OEIGINAL AETICXES. 



of continuoua woody zones, and of cambium tissue between its 

 several layers. The wood of the Salsola appears, in cross section, 

 to be spirally continuous, unlbldiug itself from the pith outwards, 

 so that a line drawn radially crosses several (five are figured) of 

 its folds. The coils are separated by a continuous cambium-layer, 

 Avhich, on approaching the periphery, divides, enclosing several 

 scattered vascular bundles. The vessels are chiefly disposed to- 

 wards the exterior margin (towards the bark) of the Avood-spiral. 

 Modifications of a structure, essentially the same as in the above 

 species, presented by JELaloxylon, Ammodendron, Atriplex, Halimus, 

 and Halostachys caspia, are described. (In the Atriplex, M. 

 Eegnault states M. Gernet to have found thirty alternating zones 

 of wood and generative tissue. I do not find him saying so : he 

 figures a smaller number. But in speaking of the structure of the 

 'false' medullary rays of this species he points out that these con- 

 sist of as many as thirty vertically superimposed cells, which appa- 

 rently confirms their character as medullary rays, but as they are 

 absent in the inner layers of the wood he cannot accept them as 

 such. D. 0.) In Halostachys, the parenchymatous rays, resembling 

 medullary plates, found in Atriplex are absent. The wood occurs 

 in concentric zones, apparently answering to years of growth, al- 

 ternating with corresponding parenchymatous rings Im- 

 portant general observations are aifixed, and attention called to 

 the manifold variety in the arrangement of the cambium system 

 in the various types of structure exhibited by the difierent genera. 

 M. Gernet calls wood in which the alburnum and duramen are 

 readily distinguishable 'heteroxylous,' — those in which the distinc- 

 tion is not apparent ' homoxylous.' — Hartig, Th. Eot. Zeit. 1859, 

 108. Wood of — Eegnault, Ann. Sc. Nat. Ser. iv. xiv. 133. Closely 

 resemble Amarantaceae in respect of the arrangement of parts. 

 They tend to differ in the structiu^e of the epiderm and suberous 

 layers. Medullary rays are absent. Campliorosma monspeliaca 

 is said to differ remarkably from the rest of the family ; its struc- 

 ture is not detailed. 

 Amaeantaceae. Link, H. F. Ann. du Museum, 1812, xix. 339. 

 Note on. — Amarantus. Link, H. P. Icoues Anat. Bot. 1837, 

 Paso. ii. X. 4-5. — linger, Fr. vide Chenopodiaceae, (linger) supra. 

 — Lindley, J. Veg. Kingdom, 510.— Ilartig, Th. Bot. Zeit. 1859. 

 108. Wood of — Eegnault, Ann. Sc. Nat. Ser. iv. xiv. 127. 

 Lestihudetia syphilitica offers an luiinterrupted liber- circle of 

 thin cells in groups of two or three : wood distributed into more 

 or less completely concentric zones, separated by belts of a com- 

 position identical with that of the outer generative layer and des- 

 titute of vessels. The vessels, marked by delicate punctuations 

 disposed in transverse lines, are arranged in radiating series 

 amongst the wood-prosenchyma, the cells of which are slightly 

 dotted. The structure oi Amarantus spinosa, and of an unknown 

 Mexican Amarantacea, is described. They all agree in the presence 



