TERTIARY LIMESTONES 125 



on one side nor the other is a friendly discussion likely to 

 degenerate into strife. 



Such discussions are of the highest value, for they 

 render possible a differentiation and consequent saving of 

 labour ; since one of the severest tasks which presents 

 itself to the scientific thinker is the invention of argu- 

 ments against his own position, in which he puts his 

 imagination to work as an adrocatus diaboli. Where 

 thinkers are ranged on opposite sides this self-imposed 

 labour may be often spared, since antagonists may 

 usually be trusted to perform it for one another, and all 

 the more efficiently for having their heart in the work. 



"We may turn then, first, to the suggestion, which we 

 owe to Professor Alexander Agassiz, who has himself 

 added immensely to our knowledge of coral reefs, par- 

 ticularly by the two works which have appeared during 

 the present year.* This is to the effect that the limestone 

 passed through by the boring in Funafuti may not all 

 belong to a continuous series of deposits, but may con- 

 sist of an upper part formed during the existing period 

 resting upon a lower part of much greater antiquity, 

 indeed of Tertiary age. Such Tertiary limestones are 

 well known ; they are said to occur in the Pacific at 

 various localities, Fiji, Tonga, and elsewhere, and pre- 

 sent characters which, fortunately for the point in 

 discussion, may be readily recognised, so that if they 

 should be present in the Funafuti core there would be 

 little difficulty in identifying them. We turn, therefore, 

 to Dr. Hinde's report, and we shall find no indication 

 that might be supposed to point in this direction, 

 but much to the contrary, and in the summary which 



* " The Coral Reefs of the Tropical Pacific," by Alexander Agassiz, 

 one vol. text, pp. xxxiii and 410, and 3 vols. plates ; also " The Coral 

 Reefs of the Maldives," one vol., 4to, pp. xxv and 168, and one vol. 

 plates, 1903. 



