856 SIR JOHN MURRAY. 



numerous explorers who, since the days of the Challenger, have probed 

 the depths of the ocean, placed their collections of muds and slimes 

 at his disposal for study and description. His familiarity with this 

 subject led him to think there are no rocks on continental areas that 

 could have been formed from such deposits as the red clays, the 

 pteropod and the Globigerina oozes, which cover vast areas of the 

 ocean's floor, where they have been accumulating for long periods of 

 geological time. This led him to the firm belief that the ocean basins 

 have remained fixed since the early ages of geology, and to a disbelief 

 in those lost Atlantes and elevated pathways called on to explain the 

 geographical distribution of land flora and fauna. Nor did he admit 

 that Australia, India, Africa, South America and Antarctica had ever 

 formed a single continent. 



Murray very naturally considered that the pendulum and geodetic, 

 observations of late years, as well as measurements of gravity over the 

 ocean, attest the permanence of the ocean basins. " For," as he wrote 

 to a friend not long before his death, " it is extremely improbable that 

 there could be such a shifting of materials in the deeper parts of the 

 crust as to cause sub-oceanic heaviness to give place to sub-continental 

 lightness — such as now is found to exist." 



He insisted that abyssal Radiolarian ooze was a different deposit 

 from those that have formed Radiolarian rocks. Although Molen- 

 graaff, in his recent papers on the Danau formation, dissents from this 

 view, he believes in the permanence of continents and ocean basins. 

 For he considers that the theory is supported by the rarity of the 

 Radiolarites, and the fact of their being limited to the geosynclinals ; 

 that is to the more mobile portions of the earth's crust, which in 

 broader or narrower strips separate the great stable areas. 



In common with most naturalists who since Dana's day have 

 examined coral reefs in the field, ^Murray returned from the voyage 

 of the Challenger convinced that Darwin's theory of subsidence did 

 not satisfactorily explain the formation of coral atolls and barrier 

 reefs, Murray's theory lays special stress on the building up of 

 marine platforms, by the gradual deposit of the remains of marine 

 organisms, to a suitable height for the growth of reef building corals ; 

 and to the seaward growth of corals on the talus, broken from the 

 living reef and rolled down its outer slope. The formation of the 

 lagoons of atolls and the passages between barrier reefs and the land 

 he attributed to the solvent action of sea water. 



^Yhen Murray, then a comparatively young man, first suggested 

 his theory, he was advised not to publish anything hastily. This 



