252 



A NATURALIST IN THE PACIFIC 



CHAP 



degree of formative energy in the development of species, since 

 only about half a dozen species are hitherto known. We find, 

 however, produced on these lofty mountains of Equatorial Africa 

 the same climatic conditions under which the arborescent Lobe- 

 liacese flourish in Hawaii, namely, the very humid atmosphere, 

 the heavy rainfall, and the mild temperature ; and if there are 

 important contrasts in their character and in the amount of differ- 

 entiation which they have undergone in the two regions, the one a 

 continental and the other an insular region, it will be from such 

 contrasts that some of the most interesting results of this com- 

 parison of a mountain of Central Africa with an island of the open 

 Pacific will be ultimately derived (see Sir H. Johnston's Uganda 

 Protectorate, 1902, and Kilimanjaro Expedition, 1886/ also Trans. 

 Linn. Soc. Bot., ser. 2, vol. 2, p. 341. 



THE LOBELIACE/E OF THE HAWAIIAN AND OF THE EAST POLYNESIAN OR 



TAHITIAN ISLANDS.* 



Hawaiian Islands. 



East Polynesian or Tahitian Islands. 



* The materials are nearly all derived from the works of Hillebrand and Drake del Castillo. Some 

 of those relating to the elevations in Hawaii are supplemented from my notes. All the genera are 

 endemic except Lobelia, of which all the species are apparently endemic, excepting perhaps one, which, 

 according to Hillebrand, resembles greatly a species from the Liukiu Islands. 



t The range of the heights of different species of Clermontia is from 5 or 6 feet for shrubs to 25 feet 

 for trees. 



J The heights attained by different species of Cyanea range from 3 or 4 feet to between 30 and 40 

 feet, thus : — 



In 8 species 3 to 6 feet. In 3 species 15 to 25 feet, 



i, 9 .. 6 .. IO >• >> 1 >> 3° 11 4° ,. 



,. 7 .1 10 ,, 15 >. 



