2 A NATURALIST ON THE "CHALLENGER." 



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

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

 portion 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 cir- 

 cumstance 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 Teneriffe, one of the 

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

 the island, on February 7th, 1873. 



Tenerift'e, Canary Islands, February Sth to 14th, 1813. — The 

 most striking feature in the natural vegetation of Teneriffe is 

 the Euphorbia canariensis. The fleshy prismatic branches of 

 this plant are devoid of leaves, have a blueish-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 (Opuntia), 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 lay 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 



