Henry H. Howorth — Elevation of Eastern Asia. 163 



small, were species of Planorhis and Limncea, apparently identical 

 with those afterwards found in the neighbourhood of Iskardo, but 

 quite different from those of the salt lake of Thogji {id. pp. 198-9). 



Cunningham not only refers to the same fact, but explains it. 

 Speaking of the former presence of wide sheets of fresh water in 

 Ladakh, he says, "Their existence is further proved by the abundance 

 oi fresh-water shells that are found in the sandy clay deposits around 

 the present salt-water lakes and on the dry plain of Kyang. These 

 shells are of two kinds, Limncea aiiricularia of all sizes and Cyclas 

 rivicola, which is only found of very small size preserved in the 

 interior of the larger shells. As these mollusca, says Cunningham, 

 do not now exist in Ladakh at a greater elevation than between 

 eleven and twelve thousand feet, it seems a probable conclusion that 

 the country must at some former period have enjoyed a very much 

 milder climate than that of the present day " (Cunningham, Ladakh, 

 p. 193). That is to say, the level of the country must have been 

 much lower. 



The kind of evidence I have here adduced might be multiplied, 

 but what I have quoted must suffice for the present, and to what 

 does it testify with most converging emphasis ? Assuredly to the 

 conclusion that the great mountain masses of Eastern Asia, with the 

 plateau they girdle and support, form a very recent feature in physical 

 geography, and that the date of their upheaval was in all probability 

 as late as the time when the Mammoth age came to an end, 

 and when the remains of that great Elephant and his companions 

 were scattered over the flanks of the Altai, and his contemporaries 

 were entombed among the snows of the Hioondes valley in far-off 

 Tibet. The evidence of this seems to me to be overwhelming, and 

 it becomes still more so when it is not only found to be consistent 

 with, but to alone explain how the former mild climate of Northern 

 Siberia was converted into a very severe one, how the great Asiatic 

 Mediterranean was drained of its waters and a large portion of its 

 bed converted into the salt-incrusted plateaux of Tibet and Kashgaria, 

 and how its drainage swept away the fauna of Northern Asia, and 

 not only drowned the animals, but buried their carcases intact under 

 continuous beds of gravel and clay over many degrees of longitude. 

 Among the sympathetic readers of my Mammoth book there have 

 been some whose judgment I highly prize, who have often asked 

 me for a cause capable of such effects as I there postulate. In regard 

 to those effects in Asia at all events, it will be admitted that, 

 granting the validity of my induction, I have produced in this and 

 recent papers, published in the Geological Magazine, a cause which 

 is competent and which explains all the facts. The argument of my 

 book extended of course beyond the limits of Asia, and perhaps I 

 may be permitted in another paper to apply the reasoning I have 

 here employed to the Great Cordillera of America. 



