42 



and similar congeners during the period, permit me to remark, 

 it was not the actual ice-clad condition of the land surface, 

 but a greater annual rainfall which Australia enjoyed that 

 ushered in these creatures upon the scene. A greater rainfall 

 implies that a more exuberant vegetation than we now possess 

 was spread over the landscape, and following the laws of evolu- 

 tion, a race of animals in every way more powerfully developed 

 is evolved to utilise it. 



Inter-glacial, or Pluvial periods — prohalle date of and dura- 

 tion. — It is now admitted by geologists and scientists generally 

 that the last glacial epoch was periodically interspersed by 

 warm intervening periods of heat. There is indubitable proof 

 from the interbedded character of the seaboard deposits, that 

 during the period of the last glaciation of the southern hemi- 

 sphere vast climatic changes occurred. As a sample of the 

 many evidences which might be here cited in favour of that 

 view, I will only instance a few which have come more promi- 

 nently before my notice. 



Kear Penfield, in the Hundred of Munno Para, section 3,170,. 

 a stratum of gravelly material was discovered at a depth below 

 the present surface of from eight to ten feet, interbedded in 

 the calcareo-argillaceous deposits of the Gawler Plains. The 

 locality in which these gravels occur evidently show that they 

 were laid there whilst Australia was enjoying a much greater 

 annual rainfall than prevails at present ; and, also, that the sea 

 level was considerably higher than it now is. Likewise, in the 

 same hundred, section 3,160, about 24 or 25 years ago a bed of 

 gravel was struck in an effort made to obtain water, about 20- 

 feet below the present surface, which was also proven to be 

 overlaid and underlaid by the usual calcareo-argillaceous de- 

 posits of the plain. G-ravels and highly water-worn boulders 

 are also to be seen exposed in the gorge cut by the waters of 

 Smith's Creek in sections 4,158 and 4,161. In this section at 

 least two beds of gravel are exposed to view, the uppermost 

 being again overlaid with from 12 to 20 feet of calcareo- 

 argillaceous material. In section 3,178, Hundred of Munno 

 Para, about eleven or twelve years ago, whilst excavating a 

 water-tank, after penetrating the calcareo-argillaceous subsoil 

 characteristic of the plain, at a depth of about six feet below 

 the surface a bed of gravel from three to four feet in thickness- 

 was struck, at the base of which indubitable evidence was- 

 shown that a fire not only had been lit there, but that it had 

 been kept in an active state of ignition for a considerable 

 period of time from the large quantity of ashes still remaining 

 within the enclosure of a few stones collected together to con- 

 stitute the primitive fireplace. Here evidence is forthcoming 

 referring to two branches of physical science. (1) The pre- 



