248 ALEXANDER AGASSIZ 



pared with that drifting along the course of the Gulf 

 Stream. I was also greatly surprised at the poverty of 

 the surface fauna. Except on one occasion, when during 

 a calm we passed through a large field of floating sur- 

 face material, we usually encountered very little. It is 

 composed mainly of Salpse, Doliolum, Sagittas, and a 

 few Siphonophores, — a striking contrast to the wealth 

 of the surface fauna to be met with in a calm day in 

 the Gulf of Mexico near the Tortugas, or in the main 

 current of the Gulf Stream as it sweeps by the Florida 

 Reef or the Cuban coast near Havana. We also found 

 great difficulty in trawling, owing to the considerable 

 irregularities of the bottom. When trawling from north 

 to south, we seemed to cut across submarine ridges, and 

 it was only while trawling from east to west that we 

 generally maintained a fairly uniform depth. During 

 the first cruise we made nearly fifty hauls of the trawl, 

 and in addition several stations were occupied in trawl- 

 ing at intermediate depths. In my dredgings in the Gulf 

 of Mexico, off the West Indies, and in the Caribbean, 

 my attention had already been called to the immense 

 amount of vegetable matter dredged up from a depth 

 of over fifteen hundred fathoms, on the lee side of the 

 West India Islands. But in none of the dredgings we 

 made on the Atlantic side of the Isthmus did we come 

 upon such masses of decomposed vegetable matter as we 

 found on this expedition. 



Cocos Island is only about two hundred and seventy-five 

 miles from the mainland, and its flora, so similar to that 

 of the adjacent coast, tells its own story. 1 Malpelo, on 

 the contrary, which is an inaccessible rock with vertical 

 sides, and destitute of any soil formed from the disinte- 



1 See page 255, second paragraph. 



