194 BULLETIN OF THE 



There was nothing in the lower part of the net which had been closed, 

 while the open part contained an unusually rich assortment of surface 

 species, and among them a large number of Scopelus, of iSchizopods, 

 and of Khizopods, mainly Collozoun and Aeanthometra. 



These experiments seem to prove conclusively that in the open sea, 

 even when close to the land, the surface pelagic fauna does not descend 

 beyond a deptli of 200 fathoms, and that there is no intermediate pelagic 

 fauna living between that depth and the bottom, and that even the free- 

 swimming bottom species du not rise to any great distance, as we found 

 no trace of anything within GO fathoms from the bottom, where it had 

 been fairly populated. 



The experiments of Chun regarding the distribution of the pelagic 

 fauna have all been made in the Mediterranean, within a compara- 

 tively short distance from the shore, and in a closed basin show- 

 ing, as is well known, special physical conditions, its temperature to its 

 greatest depths being considerably higher than the temperature of 

 oceanic basins at the limit of 200 fathoms, or thereabout, which we 

 assume now to be the limit of the bathvmetrical ran^e of the true 

 oceanic pelagic fauna. At 200 fathoms our temperature was from 49° 

 to 53°, while, as is well known, the temperature of the Mediterranean 

 soon falls at 100 fathoms even to about 56°, a temperature which is 

 continued to the bottom in this closed basin. Of course, if temperature 

 is one of the factors affecting bathymetrical distribution, there is no 

 reason except the absence of light which would prevent the surface 

 pelagic fauna from finding conditions of temperature at the greatest 

 depth similar to those which the surface fauna finds within the limit 

 of 200 fathoms in an open oceanic basin. 



Arriving as we did at the Galapngos at the beginning of a remarkably 

 early rainy season, I could not help contrasting the greeu appearance of 

 the slopes of the islands, covered as they were by a comparatively thick 

 growth of bushes, shrubs, and trees, to the description given of them by 

 Darwin, who represents them in the height of the dry season as the 

 supreme expression of desolation and barrenness. Of course, here and 

 there were extensive tracts on the sea-shore where there was nothing to 

 be seen but blocks of volcanic ashes, with an occasional cactus standing in 

 bold relief, or a series of mud volcanoes, or a huge black field of volcanic 

 rocks, an ancient flow from some crater to the sea ; but as a rule the 

 larger islands presented wide areas of rich, fertile soil, suitable for cul- 

 tivation. The experiments at Charles Island, where there is a deserted 

 plantation, and at Chatham Island, where Mr. Cobos has under success- 



