3© PEOCEEDES'GS OF THE 



I'Europe meridionale,' enumerates in the Introduction, p. x, 

 several fishes which in the Grulf of Grenoa habitually live at 

 a depth of 200-350 fothoms, adding the remarkable words 

 " where there seems to reign a constant temperature of 10^." 

 "Wliether Edward Forbes overlooked this passage in Eisso's 

 works, like almost every one of liis successors, or whether he did 

 not regard it as suflSciently trustworthy, we cannot know ; I bave 

 not found any allusion to it in his writings on the ^Mediterranean 

 fauna. Forbes joined the ^Mediterranean Survey under Captain 

 Graves in 18J:1, and during the eighteen months he was on board 

 he carried out over a hundred dredgings, some to 230 fathoms, 

 in the JEgean Sea, especially in its southern portion. His 

 labours were much facilitated by the hearty cooperation of 

 Captain Graves and of Lieut, (afterwards Admiral) Spratt, wbo 

 became a zealous pupil of Forbes. He read the report on his 

 researches before tbe British Association in 1813 *, a master- 

 piece of methodical enquiry, leading to important generalization, 

 and demonstrating for the first time the bearings of the dis- 

 tribution of marine life and of the nature of marine deposits 

 upon the study of geological strata. Forbes distinguished eight 

 vertical zones, each inhabited by a peculiar set of species ; but 

 finding that the variety of species and number of individuals 

 decreased in proportion to the depths reached, by his dredge, he 

 came to the conclusion that no life would be found beyond 300 

 fathoms, and that plants disappeared long before that depth, 

 was reached. He compared the bathymetrical zones to similar 

 Cretaceous and Tertiary layers, and explained the occurrence 

 of strata devoid, of organic remains by their having been formed 

 in azoic abyssal depths. He, like Loven, observed a distinct 

 relation between the vertical and horizontal distribution of a 

 species, viz. : tbat those species had the greatest horizontal 

 range which occurred in the greatest number of the vertical 

 zones of the same region. Altogether the spirit infused by 

 Forbes into the enquiry of marine life, and the fascinating style 

 in which he marshalled from the rich store of his knowledge 

 facts bearing upon an argument, exercised a powerful influence 

 on his contemporary fellow- workers and immediate successors. 



Everybody knows that some of Forbes's conclusions or sugges- 

 tions were based on his imperfect means of exploration. Deep- 

 sea dredging was then in its infancy ; the instruments used were 

 simple and small ; and Forbes relied chiefly on the study of 

 Mollusca, which formed the bulk of his captures. This was felt 

 already by Spratt, who succeeded Capt. Graves in the Mediter- 

 ranean Survey ; he continued to work with Forbes's apparatus in 

 the -Egean Sea and as far as Malta, dredging to 310 fathoms f. 

 He saw that the apparent scarcity or absence of life should be 

 accounted, for by the imperfection of the instruments used, and 

 expresses his belief! that life exists much lower, and that tem- 



* Brit. Assoc. Eeports, 1843, p. 30. 



t G-WTD Jeffreys, Ann. Mag. jS'at. Hist. 1870, ri. p. 65. 



I Brit. Assoc. Eeports, 1848, p. 81. 



