Notices of Memoirs — A. J. Sack — On Cone-in-Cone. 505 



the sections in casual clay-pits or chalk-pits, or in the sea-cliffs ; 

 sections which have been read almost in as many ways as there have 

 been explorei-s. No wonder that the results satisfy nobody, least of 

 all (as I know in several cases) the reporters themselves. All this 

 I quite agree in, and I hope if the Government will not find money, 

 the British Association or the Eoyal Society will do so, in order 

 that we may have some test digging. What I do object to is that 

 Mr. Jukes-Browne should transfer the burden of proof to my 

 shoulders, and that he should bid me dig, in order to supply the 

 lack of evidence for his conclusions. The burden of my paper is 

 to show that the case of those who affirm the so-called inter-glacial 

 or post-glacial existence of the Mammoth completely breaks down 

 when tested. It is, therefore, for the champions of that view to 

 find some evidence to support it which is not entirely fly-blown. 

 Those who ought to dig are those whose case is in jeopardy. No 

 one would welcome such digging more than myself, whatever its 

 results, for I never can undei-stand the pique and temper which 

 some men show when their views are no longer tenable, as if all 

 human knowledge were not more or less tentative ; and as if any 

 sensible man values an hypothesis by its finality. Let Mr, Jukes- 

 Browne, then, press on, with the help of us all, in the application 

 of a real test to the evidence in question ; and if we cannot have 

 digging, let us at all events retain our scientific credit by applying 

 adequate criticism to every statement and every fact upon which a 

 wide-reaching conclusion is based. 



isroTiGES OIF n^^Eis^ioiias. 



I. — On a Sample of Cone-in-Cone Structure, found at Picton, 

 New South Wales. ^ By A. J. Sach, F.C.S. 



THE so-called Cone-in-Cone structure, which appears to be found 

 in most countries, and which consists either of impure carbonate 

 of lime or, less frequently, of impure carbonate of iron, still awaits 

 a satisfactory explanation as to its mode of formation. It is more 

 for the sake of eliciting the opinions of the geologists now assembled, 

 than of advancing any theory of my own, that I exhibit the present 

 specimen, and offer a few remarks on its composition and structure. 



Out of some half-dozen of geological text-books that I consulted in 

 the public libraries of Sydney, that by Sir Archibald Geikie, F.R.S., 

 is the only one containing a reference to the Cone-in-Cone structure. 

 Geikie appears to adopt the opinion of Professor Marsh, who states 

 that the complex structure known as Cone-in-Cone may be due to 

 the action of pressure upon concretions in the course of formation. 



H. C. Sorby, F.R.S., in a paper read before the British Associa- 

 tion, 1859, stated that he had examined transparent sections of the 

 structure with a low magnifying power under polarized light, and 

 concluded that it was intimately connected with some kind of Oolitic 



• Eead before the Australian Association for the Advancement of Science, 

 Section C. (Geology) , Hobart, 1892. 



