333 ON THE NATUBAL. ROPES USED FOR PACKING 



by its own bark, the whole being consolidated so as to fonn a rigid cy- 

 lindrical axis, which presents no external manifestation of its peculiar in- 

 ternal organization. It is represented in the last figure of Gaudichaud's 

 ' Eecherches ' (pi. xviii. f. 21. p. 130), and has been copied into most of 

 our text-books, and ia some cases incorrectly described as a Malpighia- 

 ceous plant, as by Professor Balfour in his ' Class Book,' f 186, 1429. 



The pith and medullary sheath with its characteristic tracheal vessels 

 appear to me to be met with in the central mass only, but one of the most 

 recent observers of these stems, Herr Niigeli, has recently demonstrated 

 their presence in each of the surrounding woody masses. (Dicken- 

 wachsthum des Stengels . . . bci di^n Sapindaceen. Munich, 1864.) 



A short summary of their mode of growth, communicated to the 

 French Academy by Monsieur Netto, will be found in ' Comptes 

 Eendus,' t. 57. pp. 554-557, 21st September, 1863, from which it 

 would appear that a young stem, two to three weeks old, exhibits a 

 number of fibro-vascular bundles in the midst of an outer zone 

 of cellular tissue, one bundle being formed opposite the innermost 

 portion of each of the external grooves of the stem ; so that from its 

 very earliest stage the stem exhibits all the rudiments of the lateral 

 strands which surround the core. Aromid each of the fibro-vascular 

 bundles a mass of liber is formed, at first crescent-shaped, but after- 

 wards annular ; and by the growth and union of these several parts 

 the stem soon assumes its pecular composite character. 



Zeffuminosts. — Another group of Lianas, presenting some external 

 resemblance to the sinuous Malpighiads, is met with in plants of the 

 genera BanJunia and ScJmelln. In the Brazils they bear the name of 

 Cipo (TEscada, from their resemblance to a ladder, but Jussieu restricts 

 this name to the Schiella vuicrostachys. (' Mcnioire,' p. 118.) 



They are chiefly remarkable for depositing their woody fibres on two 

 sides only of the central pith, so that their stems have a singular flat 

 tape-like appearance, presenting in section the outline of an elongate 

 CO, the position of the pith being at the intersection of the two loops. 

 Tlie pith, however, by no means maintains its central position, for ac- 

 cording to the researches of M. Netto, the growtli of branches brings 

 about a lateral deposit of woody matter, sometimes on one side and 

 sonietimes on the other, so that the pith soon becomes eccentric. The 

 pith is generally in the form of a siiiall Maltese cross, formed of two 

 uue(jual arms, the longest of which lies in the direction of the largest 

 (li.uuctcr oF till stem. 



