MENISPEEMAGE^J. 25 



may thus become very uneven, because the later sets of bundles may 

 not, after a certain age, be produced all round a bough, but only on 

 the side where some rather large branch comes off. Hence the 

 appearance of certain old stems whose pith is excentric or even close 

 to one side ; because the unilateral development of a large number of 

 woody zones (seen as crescents in transverse section) throws the 

 greater part of the woody body to the same side. 1 Cissampelos Pareira 

 is accordiug to Decaisne organized like Cocculus. J. Hooker & 

 Thomson 2 have generally confirmed the above facts, and have shown 

 that the structure of the most closely allied types may differ as much 

 as it agrees closely in most widely different genera. 3 The pith may, 

 they say, form from one-fifth 4 to three-quarters 5 of the thickness of 

 the stem, and the number of fibro-vascular bundles varies from twelve 6 

 to seventy. 7 They are formed of dotted fibres mixed with vessels. 

 The liber bundles are more or less widely separated, and form a 

 crescent of variable curvature in transverse section ; but they 

 may be confounded into a continuous zone. 8 



To the above we must add three others, which have been im- 

 perfectly indicated, or passed over in utter silence in the study of 

 the Menispermad stems. The zone surrounding the pith is some- 

 times peculiar. Besides its being often greenish, and of a close 

 dense tissue (which characters often occur in the deep layers of the 

 cortical parenchyma, and in the medullary rays, wherewith it is 

 continuous), it is in Menispermiun formed of tough elongated 

 elements intermediate in external character between cells and fibres. 9 

 In the next place, we find in Anamirta, for instance, that the fibro- 

 vascular bundles are intermixed with well developed laticiferous 

 vessels, forming long vertical courses in the stem, and filled with a 



1 Hence the strange forms affected by the 5 In Aspidocarya. 



stems of certain species in transverse section. 6 In certain species of Cissampelos. 



(Dcne., loc. cit., t. x. fig. 17. — Gaudich., Rech. ' In Coscinium fenestratum. 



sur VOrganis. . . . des Veg., t. 18, fig. 13. — 8 The structure of the stems in Menisper- 



A. Rich., Elem., ed. 7, 154, fig. 86.) macece has been studied by a very large number 



2 Fl. Ind., i. 177. — Oliy., Stem in Dicot., 4 of authors. — Lindl., Introd. to Bot., i. 214. — ■ 

 \m Nat. Hist. Rev.,\\. (1862), 300]. The authors Maet., Gel. Anzeig. (1842), 387.— Griffith, 

 of the Flora Indica have studied the structure of Notul., iv. 305-319. — -H. Mohl, Ueb. d. Bau. 

 the stem in sixteen genera, and that usually in d. Rank. Scldingpfl. (1827), § 75. — Schacht, 

 specimens of various ages. Lehrb,, ii. 57; Die Pflanzenz., 284, t. 19; Der 



3 Thus Anamirta and Pachygone resemble Baum, 95, 199. — Eichl., in Mart. Fl. Bras., 

 Coscinium in structure ; while Parabana and Menisp., 207, t. 50, 51. 



Tinospora are as dissimilar as possible in this 9 Recalling the elements of fibrous appeai-ance 



point, though closely allied in flower and fruit. found in the medullary sheath of Lauracea. 



4 In Parabcena sagittata. 



