n6 THE BRITISH NATURALIST. [May 



conclude from the character of the markings that they were undoubtedly 

 produced by a being well acquainted with the use of a knife. Truly, 

 indeed, may we endorse the assertion of Quatrefages that " Tertiary man 

 is only known to us from the faint traces of his industry." 



Certain geologists contend that the Pliocene period was closed by a 

 series of glacial phenomena of great magnitude, which was coincident 

 with that depression which isolated England, until then one with the 

 Continent, and during which time there existed a fauna embracing the 

 Elephas Mevidionalis, the remains of which have been found in the 

 Cromer deposits. This depression, it is argued, allowed a glacial sea to 

 sweep all before it and swamp the half of the Russias, the whole of 

 Prussia, and the greater part of Holland and England. Now, the 

 course of this inundation is marked by the deposit of erratic blocks of 

 Scandanavian origin brought down by the ice floes. This glacial period 

 would be followed by a period of Continental warmth, which would 

 on account of the depression and meeting of the glaciers give rise to a 

 second period of cold, though of less intensity than the first. 



Others regard the depression of land which marked the termination 

 of the Tertiary age as being coincident with a period of mildness and 

 humidity, but whatever was the course of geological events at the time, 

 these contending sections are agreed that there did exist a period of 

 warmth. This is the first part of the Quaternary period during which 

 the waters of the various streams and rivers attained to a great height, 

 and at the same time acquired a slower mean flow, thereby allowing the 

 river deposits to accumulate quickly, and to fill in those erosions in the 

 valleys which had been brought into existence during the preceding 

 period ; while in some instances alluvium beds twenty to thirty yards 

 in thickness were laid on the banks, and deposited at the further ends 

 of the valleys. Eventually, when in time greater space was given for 

 the play of the waters, the flow became more rapid resulting in an 

 action which was the reverse of the preceding, for in place of the silt 

 and alluvium being deposited, the waters undermined those beds already 

 formed, distributing and depositing them in the ledges and on the banks 

 above the water line. These upper deposits are the earlier ones and belong 

 to the same age as the lower alluvials of the valley beds. It is in both 

 of these deposits the earliest known signs of human industry — worked 

 flints — and the remains of the Elephas aniiquus are found, and unlike those 

 unearthed from the beds of the Tertiary age, there exists no doubt as 

 to the origin of their shape. It is well that man does effectually 

 establish his identity at the commencement of the Quaternary epoch, 

 and has left abundant and indisputable traces of himself, lest certain 

 geologists, unwilling to recognize evidences less stubborn, might be in- 

 clined to name this early part of the Quaternary age the anthropozoic epoch. 



(To be continued.) 



