May 5, 1905.] 



SCIENCE. 



surface was becoming richer in animal and 

 vegetable life and also by the surface tem- 

 peratures indicating that we had reached 

 the southern edge of the cold western equa- 

 torial current. A little north of 10° south 

 latitude we made our first haul and deep 

 tow, and found a very rich fauna down to 

 the 300-fathom line, recalling the pelagic 

 fauna of the eastern lines and fully as 

 rich. On trawling we found, as we ex- 

 pected, a very rich bottom fauna. 



Among the animals brought up in the 

 trawl there were some superb Hyalonema, 

 siliceous sponges, Benthodytes and other 

 deep-sea holothurians, fine specimens of 

 Freyella, and some large ophiurans. This 

 haul is interesting as showing that in the 

 track of a great current, with abundance 

 of food, we may find at a very considerable 

 depth (2,422 fathoms) an abundant fauna 

 at very great distances from continental 

 lands. AVe were, at this station, about 

 2,140 miles from Acapulco, 1,200 miles 

 from Manga Reva, 1,700 miles from the 

 Galapagos and about 900 miles from the 

 ]\Iarquesas. 



Another haul made under the equator 

 near the northern edge of the cold current 

 in 2,320 fathoms gave us the same results. 

 The pelagic fauna was very abundant, the 

 surface teemed with radiolarians, diatoms 

 and Globigerinfe, and swai'med with inver- 

 tebrates. The trawl contained a si^perb col- 

 lection of bottom species of holothurians, 

 Brisinga, Hyalonema, Neusina, and on this 

 occasion we brought up the only stalked 

 crinoid collected during this expedition — 

 parts of the stem of two specimens of Ehi- 

 zocrimts, of which, unfortunately, the arms 

 were wanting. 



Our progress, which was excellent dur- 

 ing the first days of our journey after 

 leaving Manga Reva, has for the past six 

 days been greatly impeded by head winds 

 in the region where we ought to have been 

 in the full swing of the southeasterly 



trades. This led us, with great reluctance, 

 to abandon all idea of further work in the 

 equatorial belt of currents; to give up our 

 proposed visit to Clipperton, and on ac- 

 count of our limited coal supply, to make 

 for Acapulco, merely sounding every morn- 

 ing. This was a great disappointment to 

 me, as we had every reason to expect to be 

 able to spend some time in the region of 

 the equatorial current belts and settle more 

 conclusively than we have been able to do 

 the question of their influence upon the 

 richness of the fauna living in their track 

 far from continental shores or insular 

 areas. 



The presence of diatoms in all parts of 

 the Humboldt Current, which we crossed 

 from south of Callao to the equator at the 

 Galapagos and west towards Clipperton, 

 shows how far the track of a great oceanic 

 current can be traced, not only hy its tem- 

 perature but also by the pelagic life within 

 or near it. When once in the warm west- 

 erly equatorial current the diatoms disap- 

 pear and the bottom samples show only 

 surface radiolarians and Globigerina\ 



\Ye took a number of serial temperatures 

 in the line Galapagos-]Manga Reva, passing 

 from the colder water of the Humboldt 

 Current to the warmer waters south to- 

 ward IManga Reva. The temperatures at 

 200 fathoms became nearly identical. 

 North the great change in temperature 

 took place between 25 and 200 fathoms, 

 where there was a difference of 24°. 

 South the warm Avater extended 100 fath- 

 oms, a great change occurring between 100 

 and 200 fathoms, a drop of 16°. The se- 

 rial temperatures taken at the southern 

 and northern edges of the cold current on 

 the line ]\Ianga Reva-Aeapulco agreed well 

 with those taken in the same current to the 

 east. 



The samples of the bottom obtained by 

 the soundings taken by the expedition or 

 gatliered in the mud-b;ig and in the trawl 



