TALUS GROWTH 127 



sea-floor till it passes above the limit of, say, 45 fathoms. 

 It may then serve as a foundation for fresh reef-forming 

 growth ; this again furnishes debris to form another talus, 

 on which once more new reef will be formed, and so on, 

 the reef constantly extending seawards over fragments 

 of its dead self. 



The process is naturally a slow one, and the steep 

 slopes now existing around the Funafuti atoll (Fig. 34) do 

 not impress us as offering conditions the most favourable 

 to it. But to argue from probabilities would be a long 

 way round when a short cut is provided by the evidence 

 of the core. This is threefold. In the first place, if the 

 suggested explanation be correct, the material of the core 

 must be of the nature of talus from a depth of between 

 10 and 45 fathoms down to the bottom of 188 fathoms. 

 But between a depth of 45 and 188 fathoms organisms of 

 a different kind to those which furnish the reef-material 

 are found to flourish, and these would contribute their 

 quota to the general mass ; thus the talus would not 

 possess the same assemblage of organisms as the true 

 reef. A difference would exist which should be discover- 

 able in the material obtained from the boring ; but in 

 spite of careful search not the least sign of such a 

 difference could be detected. Professor Judd writes : 

 " Now, had any portion of the rock of the core consisted 

 of material fallen from above, and resting at lower points 

 on the ocean slope, we should expect to find an admixture 

 of these shallow-water forms that had fallen with others 

 belonging to a greater depth, which had grown on and 

 around the fallen fragments. But distinct as are many 

 of the forms of life which occur living on the ocean face 

 of the reef between 100 and 200 fathoms, not a trace of 

 these was found in the lower portions of the Funafuti 

 core. Dr. Hinde's carefully-drawn-up lists show that 

 from top to bottom the same organisms occur, sometimes 



