GEOGRAPHICAL BOTANY. 399 



of the previous herbaria have been described, may be added 

 to the descriptions of the country. The forest at Esse- 

 quibo, from which Mora excelsa projects to an altitude 

 of 160', formed the first opportunity for the traveller to 

 develope his descriptive talent. After having vividly 

 delineated the crowded growth of the trees, the climbing 

 plants and the creeping shrubs, which connect the stems 

 in impenetrable meshes, and the parasites of the fallen 

 trunks, he dwells upon a point with which we are less 

 familiar the light of tropical forests. On the ground the 

 eye would miss the splendour of the flowers of other 

 regions, and detect only Fungi, Ferns, and decaying 

 vegetable structures ; for even at noon a subdued light 

 prevails in the forest, since scarcely anywhere is a portion 

 of the sky visible through the closely-interlaced branches ; 

 but although the light is subdued beneath so dense a 

 covering of foliage, there is more light than in dark pine 

 forests. V. Kittlitz comes to the same conclusion as to 

 the remarkable and as yet but little studied question, of 

 how plants still thrive so well, and their green organs are 

 able to respire, in shaded parts of the most dense vege- 

 tation which the crust of the earth anywhere produces 

 (Vegetations- Ansichten, p. 6). " I was astonished," 

 writes he, " to find so much light beneath the noblest 

 trees, the widely- spread foliage of which scarcely any- 

 where allowed the sky to be seen. Remaining the same 

 at the most varied times of the day, it could not be 

 ascribed to the perpendicular light of noon, but only 

 to those innumerable undulations of light which, falling 

 from above through the crowded masses of leaves in every 

 direction, being reflected from stem to stem and from 

 branch to branch, finally reach the lower space in the 

 thicket, and there produce a tone of dull lustre peculiar 

 to tropical nature. In fact, what would become of that 

 whole world of plants destined to live in this shade, if 

 nature had not given the huge masses of foliage, which 

 produce it, a structure and distribution, which permits it, 

 although reflected a thousand times, still to reach in suf- 



