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pared to admit that when glaciers slid from the summits of the 

 Gawler Hills to be borne away in the shape of icebergs upon 

 the waters of some nameless inland lake, upon the floor of 

 which the earthy burden of these supposed ice-streams were 

 deposited, the contour and profile of the surrounding country 

 must have been very different from that we at present see. To 

 obtain glaciation of the Gawler Hills, one or other of the 

 following natural conditions must have prevailed : — (1) A 

 change of the present position of the poles of the earth ; (2) or 

 that our sphere was passing through a more frigid region in 

 space than now ; (3) or that the heat-producing properties of 

 the sun for the time being became greatly diminished ; (4) or 

 that the Gawler and neighbouring hills had an elevation suf- 

 ficient to retain the aqueous vapours reaching their summits in 

 a state of congelation ; (5) or a shifting northerly of the belt 

 of trade winds. In short, one or other of such must have been 

 the ruling state of nature before any part of the Australian 

 continent could be wrapt in a mantle of ice. My present 

 object is to deal only with the subject locally, and so far as the 

 evidence that Munno Para supplies the problem is left in a 

 state somewhat as follows: — It is true that no remains of 

 marine life have as yet been discovered in these beds, and 

 though it is regarded almost as a recognised maxim by the 

 geologist and paleontologist that deposits from which no fossil 

 remains have been exhumed are not of marine origin, yet I 

 am of opinion that whilst many of that class of scientists 

 advance that theory as very good negative evidence, few, I 

 presume, would for every case be prepared to uphold such as a 

 positive occurrence. Though this seeming unfossiliferous state 

 of things so far as known really does prevail throughout the 

 Munno Para Drifts, yet we must bear in mind that necessary 

 conditions are reqiiired to ensure preservation after death, in a 

 somewhat similar degree as to sustain existence during life ; 

 and that shore-lines, more especially those of a bold character, 

 must in my opinion be still less adapted for the preservation 

 and retention within their sediments of animal forms, either in 

 a fragmentary or entire state, than those of a less abrupt out- 

 line. If we reflect for a moment on the small tithe of living 

 forms that have been preserved and handed down to us in a 

 fossil state, even in beds most prolific in fossil forms, we should 

 wonder less when we find them to contain no animal remains ; 

 and we are apt to conjecture such beds were laid down under 

 such and such conditions, unwittingly overlooking the 

 important fact that their non-fossiliferous appearance is 

 not because animal remains are not present there, but because 

 they are not there in a palpable state. 



But to return from the suppositionary to a more tangible 



