LINNEAN SOCIETY OF LONDON. XXXIX 



part of the scheme, and in 1851 proceeded to London to make pre- 

 parations for his voyage. After some months spent here, during 

 which he received most valuable advice as to botanical travelling from 

 llobert Brown and other botanists, he returned to Lisbon ; and it was 

 not until August 1853 that he started on his important mission, 

 fully equipped, accredited with fuU powers by the home Government, 

 and with complete liberty of action. How well the king had chosen 

 was abundantly proved in the next seven years, during which Dr. 

 "Welwitsch showed an amount of enthusiasm, perseverance, and en- 

 durance of hardships which could scarcely be surpassed. 



He reached Loanda, the capital of Angola, in the beginning of 

 October, 1853 ; and making that town the base of his operations, he 

 at once undertook excursions in every direction, collecting plants 

 especially, but also Hymenoptera, beetles, and other insects, as well 

 as MoUusca and the higher animals. His attention was naturally 

 first directed to the country near the coast, which he carefully ex- 

 plored from the mouth of the Quizembo, a little to the north of 

 Ambriz (about 8° S.), to the mouth of the Cuauza (about 9° 30' S.). 

 He devoted nearly a year to the thorough investigation of this mari- 

 time zone, and then started for the interior, following the course of 

 the Bengo. Having reached the district of Golungo-Alto, he fixed 

 himself at a place in its centre, about 125 miles from the coast, and 

 situated in a mountainous region, called Sange, whence he made 

 expeditions, often extended to great distances. Two years were spent 

 here in arduous explorations through almost impenetrable forests, 

 during which Dr. "Welwitsch suffered repeatedly and severely from 

 endemic fevers, scurvy, and ulcerated legs ; but he never abandoned 

 his work. 



In 1856 Dr. Welwitsch left Golungo-Alto, and travelling south- 

 west through the district of Ambaca, which he found fixll of novelties, 

 reached that of Pungo-Andongo in October. Of this stage of his 

 explorations he has given a graphic sketch in the first number of 

 Mr. Andrew Murray's ' Journal of Travel and Natural History,' in 

 a paper on the " Black Rocks" 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 

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

 and spread downwards of a minute filamentous alga {Sc)jtonema 

 cJwyogntjjhictim) existing in ponds at the summit. 



Making Pungo-Andongo a centre, he passed eight months in 

 traversing the district in every direction, crossing the range of 



