Chap. IV] TROPICAL DISTRICTS CONSTANTLY MOIST 315 



form tightly stretched cords (Figs. 152, 159), which are often exceedingly 

 long but only about as thick as a lead-pencil, and are extensively used as 

 rope ('cipo' of the Brazilians) in their native country; this latter type 

 I observed in America alone, where however it was very common. In the 

 absorbing-roots in contrast with the anchoring-roots, the conducting 

 elements are strongly developed and the mechanical elements weakly 

 (Fig. 155, a). 



Besides the root-climbers mentioned, there are in the rain-forest many 

 others— of woody kinds, for instance, species of Piper and of Ficus ; of 

 herbaceous kinds, species of Vanilla and of Begonia. In tropical America 

 the species of Marcgravia, which also climb by means of anchoring-roots, 

 are widespread, and they are striking by reason of the strongly marked 

 dimorphism exhibited by the leaves, those on the branches adpressed to the 

 supporting trunk differing from those borne by the branches spreading 

 freely from it ; their peculiar inflorescences are also a remarkable feature. 



Here and there tree-trunks of the rain-forest, but only those of moderate 

 diameter, are entwined by lianes (Fig. 147). But this feature is not exactly 

 common. Most twiners stand up quite free, often as straight as an arrow, 

 between the stems of the trees, whether it be that they have raised them- 

 selves to the light on a thin stem that has since died, or at first have grown 

 up without support. Of the lofty twiners of the tropical rain-forest may be 

 particularly mentioned, Menispermaceae, Magnoliaceae (Schizandra, Kad- 

 sura), Malpighiaceae, Euphorbiaceae (Tragia, Dalechampia), Combretaceae 

 (Combretum, Quisqualis), Asclepiadaceae, Compositae (Mikania). 



The majority of large kinds of woody lianes of the tropical rain-forest, in 

 particular those with stems as thick as one's leg and lobed or cleft in cross- 

 section, belong to the highest type of climbing plants, the tendril-climbers. 

 As a rule one can recognize this character only on obtaining a view of the 

 upper portion of the climber, and this lies concealed in the branches of the 

 leafy canopy of the forest. Standing on the ground at the bottom of 

 the rope-like stem of the climber the method of attachment of its upper 

 parts is as little recognizable as is that of a ship's backstay to the mast 

 when looked at from the deck. 



Many of the most widely distributed, most striking, and largest tendril- 

 climbers both in the Old and New Worlds belong to the large genus 

 Bauhinia, the species of which — many of them hitherto undescribed owing 

 to lack of flowers — have axes with a flattened band-like form and exhibiting 

 more or less strongly marked wavy curvatures (Fig. 156). In tropical 

 America they are very common. I have seen them abundant in Brazil and 

 in the Antilles, but most of all in Trinidad, where the zigzag loops of the 

 relatively younger branches hang down from the leaf-canopy in all parts of 

 the forest. The undulations do not occur on young axes, and they disappear 

 again at an earlier or later time of life, because straight layers of wood are 



