28 COLOUR OF MARINE PLANTS. 



lages. Its eruptions were preceded by an earth- 

 quake, and violent shocks continued to be felt for 

 several years, — a phenomenon of rare occurrence, 

 the agitation of the ground usually ceasing after a 

 disengagement of lava or other volcanic products. 

 The summit of the great crater is rounded, and its 

 absolute height does not appear to be much above 

 1918 feet. The island of Lancerota was formerly 

 named Titeroigotra, and at the time of the arrival 

 of the Spaniards its inhabitants were more civilized 

 than the other Canarians, living in houses built of 

 hewn stone, while the Guanches of Teneriffe resided 

 in caves. There was then a very singular institu- 

 tion in the island. The women had several hus- 

 bands, each of whom enjoyed the prerogative be- 

 longing to the head of a family in succession, the 

 others remaining for the time in the capacity of 

 common domestics.* 



The occurrence, between the islands of Alegranza 

 and Montana Clara of a singular marine production, 

 with light-green leaves, which was brought up by 

 the lead from a great depth, affords our author, in 

 his narrative, an opportunity of stating some inter- 

 esting facts respecting the colouring of plants. This 

 seaweed, growing at the bottom of the ocean at a 

 depth of 205 feet, had its vine-shaped leaves as 

 green as those of our gramineae. According to Bou- 

 guer's experiments, light is weakened after a passage 

 of 192 feet, in the proportion of 1 to 1477-8. At the 

 depth of 205 this fucus could only have had light 



* A similar practice is stated by Mr. Fraser in liis " Journal of a Tour 

 through the Hiinala Mountains," p. 206, to occur in several of the hill 

 provinces of India. " It is usual all over the country for the future hus- 

 band to purchase his wife from her parents; and the sum thus paid 

 varies of course with the rank of the purchaser. The difficulty of rais- 

 ing this sum, and the alleged expense of maintaining women, may in 

 part account for, if it cannot excuse, a most disgusting usage, which is 

 universal over the country. Three or four or more brothers marry and 

 cohabit with one woman, who is the wife of all. They are unable to 

 raise the requisite sum individually, and thus club their shares, and buy 

 this one common spouse." 



