82 Reviews — Prof. H. Credner — on the StegocephaK. 



He goes on to say, " quantities of Mammoth tusks were observed 

 in this clay and its debris, where undermined by the stream. These 

 clays were doubtless of the same age as those in which the Mammoth- 

 remains are found at Elephant Point, over the ice-cliffs. 



In consideration for your valuable space, I refrain from quoting 

 further evidence as to the superposition of the Mammoth-beds over 

 the solid ice stratum. 



The question of the food supply necessary to the existence of the 

 extinct herbivorous mammals which once roamed those arctic 

 plains, seems to be settled by the actual existence of an abundant, 

 though arctic, flora in these apparently inhospitable wastes. 



Travellers speak of the dense thickets of willow, through which 

 they have to push their way, and also of the luxuriant growth of 

 grass covering the peaty or clayey soil. 



Moreover, Dr. Dall mentions, singular as it may seem, the fact of 

 dwarf birches, alders, 7 or 8 feet high, with stems 3 inches .in 

 diameter, and a luxuriant growth of herbage, including numerous 

 very toothsome berries, growing with the roots less than a foot from 

 perpetual solid ice. 



Sir Henry Howorth's explanation of the mode of formation of 

 these massive beds of ice by filtration of water through the soil is 

 certainly inconsistent with the structure and purity of the ice. Tbe 

 ice, 50 to 150 feet thick and upwards, where exposed in sections of 

 the cliffs, is described by several observers as pure, clear ice. Dr. 

 Dall says "the ice in general had a semi- stratified appearance, as if 

 it still retained the horizontal plane in which it originally congealed. 

 The surface was always soiled by dirty water from the earth above. 

 This dirt was, however, merely superficial." 



The facts that I have thus briefly cited are wholly opposed to Sir 

 Henry Howorth's assumption that the present is the coldest period 

 known in recent geological times in Siberia and Alaska, and further, 

 I contend that the elaborate arguments and conclusions embodied in 

 his " Mammoth and the Flood " and his "Glacial Nightmare," so far 

 as they rest on his assumption of the pre-Glacial age of the Mam- 

 moth, receive no support from the evidence derivable from North 

 Siberia and Alaska. 



I^ S ^;^ I IB AAT S. 



I. — ZUR HiSTOLOGIE DER FalTENZAHNE PALAOZOISCHER SteGO- 

 CEPHALEN. 



On the Histology of the plicated (folded) teeth of Stegocephali. 

 By H. Credner. Abhandl. der mathemat.-physischen Classe 

 der K. Sachsischen Ges. der Wissenschaften. Band xx. No. iv. 

 Mit vier Tafeln und fiinf Textfiguren. Koyal 8vo. pp. 477- 

 552. (Leipzig, 1893.) 



WITHIN the last thirteen years Professor Credner has made us 

 acquainted with the Stegocephali and Saurians of the 

 Permian limestone near Dresden, from the smallest salamandrine 



