MURRAY: ALEXANDER AGASSIZ. 149 



he concluded that the Caribbean Sea was at one time a bay of the 

 Pacific Ocean, and that since Cretaceous times it had been cut off 

 from the Pacific by the uprise of the Isthmus of Panama. 



When the "Challenger" Expedition carried her explorations down 

 through the central Southern Pacific, she found a rather puzzling 

 state of things. In deep water relatively very few animals were 

 captured on the bottom of the ocean when compared with those 

 taken in the Great Southern Ocean or nearer continental shores; 

 those obtained were, however, of rather pronounced archaic types. 

 The deposits in the same area were of surpassing interest; large quan- 

 tities of a deep-brown clay were hauled up, in which were imbedded 

 enormous numbers of manganese nodules and concretions, some of 

 them being formed around sharks' teeth, earbones and other bones of 

 whales, and others around volcanic fragments mostly converted into 

 palagonite. Sometimes hundreds of sharks' teeth and dozen of 

 whales' earbones were captured in a single haul, and most of them 

 belonged to extinct species. Small zeolitic crystals and crystal balls 

 were also mixed up in these red-brown clays, evidently formed in situ. 

 More extraordinary still were the minute spherules having a hard 

 black coating and an interior of pure iron and nickel, as well as 

 other minute spherules, called chondres, found hitherto only in 

 meteorites. These spherules are believed to have an extra-terrestrial 

 origin, and to have formed at one time the tails of meteorites or falling 

 stars. This was a strange assemblage of things, and some scientific 

 men argued that such a condition of matters must be regarded as 

 local and accidental. 



Now Alexander Agassiz explored anew this region of the earth's 

 surface the furthest removed from the shores of continental land, 

 and he found that the same condition of things extended over vast 

 areas of the Pacific Ocean. Here we have almost certainly the region 

 of minimum accumulation on the sea-floor, and recent investigations 

 indicate that there is in these deep deposits more radio-active matter 

 than anywhere else in the solid crust of our planet. A satisfactory 

 and clear understanding of the phenomena has not yet been obtained, 

 but Agassiz's researches take us a long way on the road to a solution 

 of some exceedingly interesting and important oceanic problems. 



During the last thirty years of his life, Agassiz became very greatly 

 interested in all coral-reef problems, and organized very many ex- 

 tended expeditions, almost entirely at his own expense, with the view 

 of studying coral reefs, coral islands, and upraised coral formations. 

 It would be wearisome to give even an abstract of all the publications 



