2 TENERIFE. 



shortly as a whole, and where oceanic animals and plants 

 will also be treated of to some extent. 



The voyage of the " Challenger " occupied three years and 

 155 days, and out of this period about 520 days, or portions 

 of these, were available for excursions on shore. A very large 

 proportion of the time in harbour was necessarily spent at 

 places where dockyards and workshops were available for 

 repairs to the ship. The stays made at less-frequented places 

 of especial interest to the naturalist were comparatively short. 

 This circumstance should be borne in mind by the reader. 



After stopping at Lisbon, Gibraltar, and Madeira — which 

 latter island was afterwards visited a second time, and will be 

 referred to in the sequel — the ship reached Tenerife, one of 

 the Canary Islands, and anchored off Santa Cruz, the chief 

 town of the island, on February 7th, 1873. 



Tenerife, Canary Islands, February 7th to 14th, 1873.— The 

 most striking feature in the natural vegetation of Tenerife is the 

 Eiiphorbia canariensis. The fleshy prismatic branches of this 

 plant are devoid of leaves, have a bluish-green colour, and 

 are perfectly straight and perpendicular, being disposed side 

 by side, and 10 or 15 feet in height. The plant is abundant 

 all over the rocks at a low elevation, and resembles a cactus 

 in appearance. It has an abundant milky juice, which is very 

 acrid and poisonous. Of the introduced vegetation, the planta- 

 tions of the broad-lobed cactus {Oj>it7itia), employed for the 

 raising of the Cochineal insect, are curious. The crop of 

 insects was, in the month of February, just being started on 

 the plant, that is to say, the female insects were being placed 

 upon the leaf-shaped lobes of the plant to lav their eggs, and 

 start a fresh brood. The females are, when thus put out at 

 the beginning of the season, held on to the plants by means of 

 white rags tied round the lobes. Hence the fields, when seen 

 at a distance, look as if they contained some crop bearing a 

 continuous sheet of large white blossoms. I was greatly puzzled 

 by them when looking at them as the ship was approaching the 

 island. The island is so steep and rocky that it has been 

 terraced for purposes of cultivation, and nearly every available 

 spot has been treated in this manner. 



I accompanied a party on an excursion up the Peak. The 

 way led from Santa Cruz, through the Cochineal fields, and up 

 a steep but well-engineered road, planted with tamarisk trees to 

 the summit of the central ridge of the island. Here was passed 

 a dilapidated town, thoroughly Spanish in its architecture, with 

 some fine houses in it in a ruinous condition. The central 

 square of the town was overgrown with weeds, and its streets 

 mostly covered with grass ; but so are many in the capital, 



