26 Sir H. H. Howorth—The True Horizon of the Mammoth. 
detached from it and which are found like boulders in the clay, 
sometimes such portions being several yards in size, is also true, 
but I have failed to find evidence of a Drift-bed underlying a dirt- 
bed tn situ. 
The very great majority of cases known, depend on such unsatis- 
factory evidence as well-sections. It is not wonderful, therefore, 
that there should be a feud among the American geologists as to the 
reading of the facts. The State geologists of Indiana recognize only 
one forest-bed, and declare that it underlies the Drift. 
In Illinois the evidence is most unsatisfactory. I will give one 
of the most typical cases relied upon by Professor Geikie in his 
defence of interglacial beds. “In Perry County, Illinois, Mr.’ 
Worthen describes a bed of blue sand with leaves and sticks as 
occurring below the main mass of Drift. This bed, he continues, 
usually lies at the bottom of the Drift deposits, but at one point in 
Jackson County it was underlaid by a bed of sand two or three feet 
in thickness.” It is assuredly a brave thing to postulate that the 
occurrence of a bed of sand is in itself evidence of the dirt-bed 
being underlaid by Drift. In Woodford County a similar accumula- 
tion of peaty matter was found at a depth of about 65 feet below 
50 feet of hard-pan. In Ohio, Mr. Charles Whittlesea tells us how 
he had examined 59 wells in 1844, of which only six, or 10 per cent., 
showed traces of dirt-beds, leaves, timber, or silt. While he names 
several instances of logs of wood being found imbedded in the till, 
I cannot find any case where dirt-beds are stated by him to have 
been underlain by Drift, while all are stated to have been covered 
by deep beds of Drift. 
Dr. Wright, ‘‘ who has written so admirably on the glacial age in 
America, says a thorough study of the condition and distribution of 
the buried forests, bears strongly, as I cannot but think, against the 
complete separation of glacial epochs in North America.” 
Mr. C. R. Gilbert, a distinguished American geologist, says: ‘ In 
America, where there is great activity in the investigation of glacial 
phenomena the evidence of a single interglacial period is cumulative 
and overwhelming, while there is no indication whatever of more 
than one.” The American case as thus summed up is consequently 
completely at one with the European one; and it must be allowed, 
I think. that if there be here and there cases which appear to point 
to a different conclusion they are distinctly sporadic exceptions to a 
widespread law, and as such ought to be sifted and criticised with 
the greatest care and completeness, and that it is for those who still 
maintain a post-Glacial or inter-Glacial existence of the Mammoth 
to prove their case. 
I have here and elsewhere in these papers used the words post- 
Glacial and inter-Glacial in their commonly accepted sense, as 
meaning that the Mammoth lived after the deposition of the Drift 
or lived between two such successive depositions. When I say that 
the facts inevitably point to the Mammoth beds when in situ always 
underlying the Drift, I do not mean that the Mammoth preceded 
the so-called Glacial age. I have written a very big book to try and 
show that it is contrary to the physical qualities of ice to suppose 
