90 A NATURALIST IN MID-AFRICA. 



to a black morass ; and I had to remain for four 

 or five days, too weak to move, and wondering 

 what on earth had induced me ever to come. 



Then at last I struggled up to the forest and 

 managed to get to about 7,000 feet, where 

 I found myself in a new world. There was the 

 common English Sanicle, a beautiful Meadow 

 Rue, a Cerastium, and many other plants which 

 induced me to believe that I should really bring 

 back something of interest. 



The presence of forms like these almost on the 

 equator involves certain facts that are rarely 

 realised ; perhaps less clearly by systematic 

 botanists than by quite unscientific people. How 

 did they get there ? 



It is not hard to see why they were able to 

 live at this altitude, even on the equator, pro- 

 vided they were once introduced, because even 

 at 7,000 feet the temperature is not very 

 different from that of England. There is, more- 

 over, no lack of moisture, which would pro- 

 duce the desert type of plant, especially when 

 combined with heat ; nor is there the excess of 

 it and the steaminess found, for instance, in the 

 Wimi valley (see p. 100), by which the cha- 

 racteristic tropical forest would be formed. In 

 essentials, in short, the climate is fairly moist, 

 not unlike Southern Europe in July ; and I 

 found these plants flowering in the same month 

 as their cousins far away in Dumfriesshire. 



