102 A NATURALIST IN MID-AFRICA. 



treme beauty of this gorge. I went a consider- 

 able distance up the river and found it one of the 

 most interesting of all. There are probably 15 

 miles at least of virgin forest, and the valley is 

 usually 3 miles wide. About two hours from my 

 camp I was much astonished to find myself in a 

 glade of tree ferns (Cyathea sp.. nov.). Some of 

 these were 20 feet high ; all were covered with 

 soft green moss and quantities of Peperomias, 

 Begonias, and ferns of all possible different shapes. 

 The wetness of everything was indescribable. One 

 can form - a fairly good idea of this valley by enter- 

 ing a conservatory, e.g., the Fernhouse at Kew 

 Gardens. So far as I could gather, the conditions 

 are very much those of the Carboniferous age. 

 They may be roughly described as a " dim hot 

 steaminess." Although it is apparently fanciful, 

 it is none the less literally true, that there has 

 been a continuity of climate and physical con- 

 ditions from that ancient date to the present, 

 though the climate and conditions may have 

 migrated over a whole continent in the interval. 

 I have, seen such places in West Africa and 

 Madagascar, and also — though scarcely so marked 

 -in the lowest and most sheltered spots of the 

 Perie bush in South Africa, and everywhere one 

 finds something of the same kind, an abundance 

 of cryptogams of all kinds, Peperomias and a few 

 other plants. Amongst the latter is a very deli- 

 cate, slender orchid, which always lives on wet leaf 



