24 NOTES OF A NATURALIST. 



addition whose amount experience alone can fully 

 determine. The only race combining physical strength 

 with any moderate adaptation to the climate is ap- 

 parently the African negro, and even with these the 

 amount of sickness and mortality is said to be alarm- 

 ingly great. The field from which negro labour can 

 be recruited, though large, is by no means unlimited, 

 and it is to be expected that the rate of wages must 

 be considerably increased as time advances. The 

 conditions of the problem have no doubt been care- 

 fully studied by the remarkable man to whom its 

 existence is due, and by the able assistants whom he 

 has consulted ; but it may not be too rash to hazard 

 the prediction that, apart from any international 

 difficulties, its success may depend upon the more or 

 less complete realization of two desiderata — first, the 

 extensive application of labour-saving machinery, for 

 which perhaps the heavy rainfall may supply the 

 motive power ; secondly, the possibility, by completely 

 clearing the summits of some of the higher hills near 

 the line, of establishing healthy sites whence workmen 

 could be conveyed to the required points during the 

 day and brought back before nightfall. 



Nothing in our brief experience suggested the idea 

 of an especially unhealthy region, and the feelings of 

 a botanist at being whirled so rapidly through a land 

 teeming with objects of curiosity and interest are 

 better imagined than expressed. For more than half 

 the distance the line is simply a trench cut through 

 the forest, which is restrained from invading and 

 burying the rails only by constant clearing on either 

 side. The trees were not very large, but seemed to 



