214 MALPIGHIADS COCCULUS. [BOOK i. 



plants to be in like manner divided into a number of regular 

 lobes, which however, actually reach the axis ; and, in conse- 

 quence of the twining habit of the stem, are twisted into the 



fig. 40. 



appearance of a cable externally. In fact, the formation of 

 longitudinal vertical plates or ribs (or, when old, buttresses) 

 in Exogens, although unknown in Europe, is by no means of 

 uncommon occurrence in tropical countries. The Ceiba Trees, 

 (Bombax) are remarkable examples of it, their longitudinal 

 projections extending far enough to conceal men in the 

 angles, and Sir Robert Schomburgh found in Demerara a 

 forest tree in which sections of even the young branches 

 form a very regular five-armed Maltese cross. 



In Cocculus laurifolius (fig. 41.) the concentric lines 



fig. 41. 



evidently belong to the medullary system ; they are ex- 

 tremely interrupted and unequal, often only half encircling 



