142 Correspondence—Mr. Jukes-Browne—Mr. W. Shone. 
superjacent patches of Boulder-clay to be in place? Unless he 
refuses credence to the observations of Messrs. Prestwich, H. B. 
Woodward, and C. Reid, he cannot support Sir H. Howorth. 
I have confined myself to denying Sir Henry’s contention that 
Mammoth-bearing deposits are ‘‘never underlain by Glacial Drift.” 
I am perfectly prepared to admit that Mammoth-remains do occur 
under undoubted Glacial deposits, as Dr. Hicks maintains, but that 
is not the point in question. A. J. Juxes- Browne. 
Exeter, Fed. 7, 1893. 
A BORING AT WILLOUGHBY IN LINCOLNSHIRE. 
Srr,—I think you will find that the boring at Willoughby, men- 
tioned in the paragraph quoted from the “Morning Post” in the 
GrotocicaL Macazine for February, was made in 1887. J have 
some particulars of the strata passed through which I hope to publish 
shortly, and will only now say that it supplies valuable information 
about the subterranean structure of that part of Lincolnshire. The 
boring passed directly from Glacial Drift into the so-called Neo- 
comian, without the intervention of any kind of Chalk. Water was 
found at the top of the Spilsby Sandstone. 
Exersr, Fvb. 7. A. J. Jukes-Browne. 
SUBTERRANEAN EROSION. 
Srr,—In the Grotocican Macazine for September, 1892, Mr. 
Morton, F.G.S., criticised a paper I read in December, 1891, before 
the Geological Society, entitled “‘The Subterranean Erosion of the 
Glacial Drift, a probable cause of Submerged Peat and Forest Beds ” 
(Quart. Journ. Feb. 1892, pp. 96-103). So far as Mr. Morton’s 
criticisms partake of the nature of a defence of his theory of the 
origin of the submerged Peat and Forest-beds of Lancashire and 
Cheshire as described in his work entitled “‘The Geology of the 
Country around Liverpool” I do not propose to discuss, for if Mr. 
Morton’s theory be right then my theory must be wrong, and 
vice versa. 
Mr. Morton’s remarks, however, go beyond the mere local appli- 
cation of the principle of subterranean erosion. In concluding, he 
writes, ‘It is very remarkable that such an active agent has not 
been observed in Tertiary formations of the South of England where 
the beds of clay and sand are similar and occur under the same 
conditions.” I go further even than Mr. Morton, viz.—If the 
principle of Subterranean Erosion be true at all it will prove as 
true in the past as in the present (under the conditions mentioned) 
and as wide in its operations as the law of gravitation. In the 
Quart. Journ. of the Geol. Soc. vol. xlviii. p. 103, I defined Subter- 
ranean Hrosion as follows :— 
«That wherever water percolated through such unconsolidated 
beds as clays, sands, and gravels, along an inclined plane, it was con- 
stantly carrying the lighter materials of such strata towards the 
nearest point of escape. The nearer the approach to the point of escape, 
