(>98 LOUIS AGASSIZ. 



less interested than other naturalists have been 

 in the old question so long asked and still 

 unanswered, about the Sargassum. " Where 

 is its home, and what its origin? Does it 

 float, a rootless wanderer on the deep, or has 

 it broken away from some submarine attach- 

 ment ? " He had passed through the same 

 region before, in going to Brazil, but then he 

 was on a large ocean steamer, while from the 

 little Hassler, of 360 tons, one could almost 

 fish by hand from the Sargassum fields. Some 

 of the chief results are given in the following 

 letter. 



TO PROFESSOR PEIRCE. 



ST. THOMAS, December 15, 1871. 



... As soon as we reached the Gulf Stream 

 we began work. Indeed, Pourtales had organ- 

 ized a party to study the temperatures as soon 

 as we passed Gay Head, and will himself re- 

 port to you his results. My own attention 

 was entirely turned to the Gulf weed and its 

 inhabitants, of which we made extensive col- 

 lections. Our observations on the floating 

 weed itself favor the view of those who be- 

 lieve it to be torn from rocks, on which Sar- 

 gassum naturally grows. I made a simple 

 experiment which seems to me conclusive. 

 Any branch of the sea- weed which is deprived 





