INTRODUCTION. XI 



of the University of Coimbra ; in recognition of this service he 

 was on the 1st March 1855 elected Corresponding Fellow of the 

 Coimbra Institute. 



He devoted nearly a year to the thorough investigation of the 

 maritime zone, and then started, on the 10th September 1854, 

 for the interior, following the course of the Bengo. Having 

 reached the district of Golungo Alto, he ultimately fixed himself 

 at a place called Sange, about 125 miles from the coast, in a 

 mountainous region, whence he made excursions to Cazengo, on 

 the banks of the Luinha, and numerous other expeditions, often 

 extended to great distances. During his stay here he for some 

 weeks enjoyed the company of Livingstone, who, in his book of 

 missionary travels, bore testimony to Welwitsch's arduous labours 

 and abilities. Two years were occupied in Golungo Alto with 

 these laborious explorations through almost impenetrable forests, 

 during which Welwitsch suffered repeatedly and severely from 

 endemic fevers, scurvy, and ulcerated legs, the usual concomitants 

 of African travel; but he never abandoned his work. In this 

 mountainous region, whose highest peaks rise more than 2000 feet, 

 above 300 different species of trees and more than 400 kinds of 

 climbing plants, closely entwined, form a magnificent primeval 

 forest, the ground being luxuriantly overgrown with more than 

 60 species of ferns, partly of arborescent forms. 



On the 11th October 1856, Welwitsch left Golungo Alto, and, 

 travelling south-west through the district of Ambaca, which he 

 found full of novelties, reached Pungo Andongo on the 18th 

 October. Of this stage of his explorations he gave a graphic 

 sketch, in Andrew Murray's Journal of Travel, in a paper on the 

 " Black Bocks " of the district, from which it received its old 

 name of the Presidio das Pedras Negras. The annual blackening, 

 after each rainy season, of these masses of gneiss, 300 to 600 feet 

 in height, he found to be caused by the immense increase and 

 downward spread of a minute filamentous alga (Scytonema choro- 

 graphicum), existing in ponds at the summit. The flora of . this 

 " beautiful secluded El Dorado " is described in glowing terms 

 by the traveller. "I should call Pungo Andongo a botanical 

 garden, in form of an extensive park, in which are found the 

 most interesting treasures of vegetation, from the various districts 

 of tropical and subtropical forms of vegetation, judiciously grouped 

 together, with a considerable number of forms of vegetation quite 

 peculiar to itself." 



Making this paradise a centre, he passed nearly eight months 

 in traversing the district in every direction, crossing the singular 

 range of Pedras de Guinga (27th January 1857), the banks of 

 the Lombe (7th and 8th March) and the Cuige, and penetrating 

 as far as the charming islands of Calemba (12th to 16th March), 

 in the Cuanza, and the immense forests which stretch from 

 Quisonde to Condo (12th to 17th March), near the cataracts of 

 the river Cuanza. This point, about 250 miles from the coast, 

 was the farthest to the east reached. On his way back to Pungo 



