220 PROCEEDINGS OF SOCIETIES. ["ia'i. Apduffi^ 



external groves of the stem ; so that from its very earliest stage the 

 stem exhibits all the rudiments of the lateral strands which surround 

 the core. Around each of the fihro-vascular bundles a mass of liber 

 is formed, at first crescent-shaped, but afterwards annular ; and by 

 the growth and union of these several parts the stem soon assumes its 

 peculiar comjjosite cliaracter. 



Leguminoscc. — Another group of lianas, presenting some external 

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

 belong to this natural order of the genera BauJdnia and Sclmella. In 

 the Brazils they bear the name of Cijpo d'Escada, from their resem- 

 blance to a ladder, but Jussieu restricts this name to the Schnella 

 macrostacJiijs.* 



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 elon- 

 gate oo, the position of the pith being at the intersection of the two 

 loops. The pith, however, by no means maintains its central position, 

 for according to the researches of M. Netto, the growth of branches 

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

 and sometimes on the other, so that the pith soon becomes eccentric. 

 The pith is generally in the form of a small Maltese cross, formed of 

 two unequal arms, the longest of which lies in the direction of the 

 largest diameter of the stem. 



There are many other forms of Bauhinia, many of which will be 

 found figured in the standard works of Lindley, Schleiden, Richard, 

 Duchartre, &c. 



Aristolochiacece. — It is very likely that this natural order has re- 

 presentatives amongst these ropes ; at least to it I refer for the pre- 

 sent two species remarkable for their very striking medullary rays. 



In both species these rays proceed from the pith to the bark, 

 increasing in breadth and volume as they recede from the pith, so 

 that by the time they reach the bark they become of considerable 

 thickness. 



In one species, whose wood has a reddish tinge, there are about 

 nineteen or twenty of these magnificent rays in a stem exceeding half 

 an inch in diameter ; the intermediate spaces are filled up with woody 

 fibres in which occur large vessels. In this sjiecies secondary medul- 

 lary rays rarely make their appearance. But in the other sj^ecies, 

 which has a beautiful cream-coloured wood of the shade of onr com- 

 mon holly, secondary and tertiary medullary rays make their apj)ear- 

 ance, so that in a stem three-quarters of an inch in diameter there will 

 be as many as thirty primary rays, and as many more secondary rays. 

 In this, the commoner species of the two, the cortical system is much 

 thicker than in the first-mentioned si)ecies. Both bear much resem- 

 blance to a wood-section in my cabinet which is called " New Zealand 

 Pepper," a plant of which I am quite ignorant. 



Ampelidece.. — Gaudichaud in his memoir f gives a figure of the 

 Cissus hydropJiora as one of the common lianas of the Brazil, but I 

 am not sure whether it occurs amongst the roi^es which reach this 

 * 'Memoirc,' p. 118. f ' Rcchcrclits,' pi. xiii., fig. 5, p. 100. 



