Agassiz — Albatross Expedition to the Eastern Pacific. 275 



current. The great changes of temperature which took place 

 in the layers of the water between 50 and 300 fathoms are 

 most striking, and show what a disturbing element the great 

 mass of cold water flowing north must be in the equatorial 

 regions of the Panamic district to the south and to the north 

 of the Galapagos. South of the Galapagos the western flow 

 of the Humboldt current must be nearly 900 miles wide, and 

 of about the same width when running parallel to the South 

 American coast. 



The range of temperatures between 30 fathoms and 150 

 fathoms is at some points as great as 21°. Such extremes can- 

 not fail to affect the distribution of the pelagic fauna, and may 

 account for the mass of dead material often collected in the 

 intermediate tows at depths of less than 300 fathoms, when the 

 range becomes as great as 28°. Such a range of temperature 

 is far greater than that of the isocrymic lines which separate 

 coast faunal divisions. The bottom fauna, as we entered the 

 Humboldt current going north, gradually became richer in 

 spite of its being covered with manganese nodules. 



The two lines centering at Easter Island developed the 

 Albatross Plateau indicated on the Challenger bathy metrical 

 charts, on the strength of a few soundings reaching from 

 Callao in a northwesterly direction and of a couple of sound- 

 ings on the 20th degree of latitude. The Albatross Plateau is 

 marked as a broad ridge separating the Buchan Basin from the 

 deep basin to the westward, of which Grey Deep and the 

 Moser Basin are the most noted areas. 



Our line from Easter Island to the Galapagos showed a won- 

 derfully level ridge, varying in depth only from 2,020 to 2,265 

 fathoms in a distance of nearly 2,000 miles. The soundings 

 we made to the eastward from the Galapagos to the South 

 American coast, and to the westward of Callao, as well as on 

 the line from Callao to Easter Island, all indicate a gradual 

 deepening to the eastward to form what the Challenger has 

 called the Buchan Basin with the greatest depths of 2,400 to 

 over 2,700 fathoms and passing at several points near the coast 

 to Milne-Edwards Deep, Haeckel Deep, Krummel Deep, and 

 Bichards Deep, some of them with a depth of over 4,000 

 fathoms. According to the Challenger soundings the Juan 

 Fernandez Plateau connects with the Albatross Plateau and 

 forms the southern limit separating Buchan Basin from the 

 Barker Basin to the south of the Juan Fernandez Plateau. 



At Easter Island we found our collier awaiting our arrival. 

 We moved from Cook Bay to La Perouse Bay to coal, as there 

 was less swell there than in Cook Bay, where we could scarcely 

 have gone alongside for this purpose. 



Considerable shore collecting was done at Easter Island. 

 AYe must have brought together at least 30 species of plants. 

 The flora of Easter Island is very poor. There are no trees 



