COTTON BALES IN THE BRAZILS. 333 



There are other forms of Banhiniu, many of which will be found 

 figured in the works of Lindley, Schleiden, Richard, Duchartre, etc. 



Aristolochiacea. — To this I refer for the present two species remark- 

 able for their very striking medullary rays. 



In both species these increase in breadth and volume as they recede 

 from the pith, so that by the time they reacli 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 species secondary medullary 

 rays are rarely found. But in the other species, which has a beautiful 

 cream-coloured wood of the shade of our common Holly, secondary and 

 tertiary medullary rays make their appearance, 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 coitical system is much thicker than in the first men- 

 tioned species. Both bear much resemblance to a wood-section in my 

 cabinet which is called " New Zealand Pepper," of the position of 

 which I am ignorant. 



A)Hpellde(e. — Gaudichaud in his memoir (' Recherches,' pi. xiii. fig. .5. 

 p. 109) gives a figure of the Gissus liydropliora as one of the common 

 Lianas of the Brazil, but I am not sure whether it occurs amongst the 

 ropes which reach this country. It is described by M. Netto (Ann. des 

 Sc, 5th ser. Bot. t. vi. p. 320 ; ' Comptes Rendus,' t. 62. p. 1076) 

 There is one histological character presented by this Liana which wil 

 lead to its identification, and that is the abundant quantity of raphi- 

 dian crystals contained in all parts of the stem. M. Netto describes 

 the form of these as needle-shaped, but bifurcate at one extremity. 



However abnormal many of the stems belonging to these various 

 Orders may be, there can be no doubt that tlie characteristic elements 

 of the dicotyledonous stem are present during some portion of their 

 lives. Their unequal development may be brought about either by 

 the vital energy of the growing tissue of the bark being in excess of 

 that of the wood, or vice vend ; or it may be produced by a much 

 more copious deposition of woody tissue at some points of the circura- 

 feren(*e than at others, from which will result the ciu'ious forms pre- 

 sented by the Baidtuiias and many of the JSIalpujldacea. 



