196 BULLETIN OF THE 



to the immense amount of silt which is brought down the hill and moun- 

 tain sides every rainy season, and which simply covers the Hour of the 

 ocean to a very considerable distance from the land, the land deposits 

 being found by us even on the line from the Galapagos to Acapulco at 

 the most distant point from the shore to the side or extremities. The 

 mud in Panama Bay to the hundred-fathom line is something extraordi- 

 nary, and its influence on the growth of coral reefs is undoubtedly greatly 

 increased from the large amount of decomposed vegetable matter which 

 is mixed with the terrigenous deposits. 



The course of the currents along the Mexican and the Central and 

 South American coasts clearly indicates to us the sources from which the 

 fauna and flora of the volcanic group of the Galapagos has derived its 

 origin. The distance from the coast of Ecuador {Galera Point and Cape 

 San Francisco) is in a direct line not much over 500 miles, and that 

 from the Costa Rica coast but a little over 600 miles, and the bottom 

 must be for its whole distance strewn thickly with vegetable matter. 

 The force of the currents is very great, sometimes as much as 75 miles 

 a day, so that seeds, fruits, masses of vegetation harboring small rep- 

 tiles, or even large ones, as well as other terrestrial animals, need 

 not be afloat long before they might safely be landed on the shores of 

 the Galapagos. Its flora, as is well known, is eminently American, while 

 its fauna at every point discloses its affinity to the Mexican, Central or 

 South American, and even West Indian types, from which it has proba- 

 bly originated ; the last indicating, as well as so many of the marine 

 types collected dui'ing this expedition, the close connection that once 

 existed between the Panamic region and the Caribbean and Gulf of 

 Mexico, 



I have already referred to the physiognomy of the deep-sea fauna, 

 showing relationship on the one side to Atlantic and West Indian types, 

 and on the other to the extension of the Pacific types, which mix with 

 the strictly deep-sea Panamic ones. The western and eastern Pacific 

 fauna, while as a whole presenting very marked features in common, yet 

 also present striking differences. The vast extent of territory over which 

 some of the marine types extend, through all the tropical part of the 

 Pacific, may readily be explained from the course of the great western 

 equatorial current and the eastern counter current, which cannot fail 

 to act as general distributors in space for the extension of a vast number 

 of marine Vertebrates and Invertebrates. 



Mr. Townsend made quite a large collection of Birds from Chatham 

 and Charles Islands, considering the short time we were there. 



