160 Mr. F. Du Cane Godnian on the Resident and 



England, as there are constantly steamers from Liverpool to the 

 African coast, most of which call at either Madeira, Teneriflfe, or 

 Gran Canary, and there are also the regular Portuguese and 

 Spanish mail-steamers. To a naturalist these isolated spots 

 have an interest not possessed to the same extent by conti- 

 nents, inasmuch as they are more capable of throwing light 

 on the important question of geographical distribution. 



All the Atlantic islands are volcanic, and consequently moun- 

 tainous ; and in some the traces of recent volcanic eruptions fall 

 within the historic period. In others there are large tracts of land 

 covered with cinders and scoriae almost destitute of vegetable 

 life, whilst, again, in others, where the eruptions are of older date 

 and the lavas more disintegrated, vegetation is exceedingly luxu- 

 riant. To the stranger, perhaps, one of the most striking features 

 is, that there is scarcely a flat piece of ground throughout, but the 

 whole surface is broken up into innumerable abrupt mountains 

 and hills varying in height from the Peak of TenerifFe, which 

 attains an altitude above the sea-level of more than 12,000 feet, 

 down to small conical hills of ashes not exceeding 100 feet in 

 height. 



The climate of the Canaries near the coast, and more espe- 

 cially of the eastern islands, is very dry, and during a great 

 part of the year little or no rain falls iu the vicinity of the sea ; 

 while, in consequence of the continual north-east trade winds 

 to which all the islands are subject for a great portion of the 

 year, a dense belt of mist forms and rests upon the mountains 

 at a height of about 3000 feet above the sea. This remains 

 throughout the whole day, and casts a gloom upon the mountain 

 scenery ; but usually during the night this cloud clears away, and 

 at sunrise the highest peaks are fi'equently visible. Soon after 

 sunrise, however, the clouds form again, and the same state of 

 things succeeds. This cloud is some 3000 to 4000 feet iu 

 thickness, or extends to a height of 7000 feet above the sea, and 

 from the lower portions of TenerifFe (and also of the other 

 islands) obscures all view of the highest peaks of the mountain- 

 tops. Above 7000 feet a wind constantly blows from the 

 south-west, overlaying the north-cast trades — a wind nearly 

 destitute of moisture. Thus it frequently happens that the 



