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now lie. This is my opinion concerning their appearance, 
which I have often attentively considered.” 
The literature upon the subject of these stones is volu- 
minous, but probably the most exhaustive paper is by Professor 
Prestwich, in Vol. X. Quarterly Journal. He there shews that 
they occur in the Reading and basement beds of the London 
clay, but they are mostly derived from the Bagshot sands, and 
at one time the Kocene strata extended over the Chalk Downs 
of the South and West of England, and the Sarsen stones have 
been left by denudation not far from their parent source. 
They are formed of concretionary masses of hard Saccharoid 
Sandstone, full of small grains of quartz, and vary in colour 
from white, a pale grey, to brown. 
Professor Rupert Jones mentions in the Geological Magazine 
for 1876 that one of the enormous upright sarsens (standing 
among the ricks of a farm) abounds with peculiar perpendicular 
rootlets, together with numerous horizontal casts of stems and 
other plant remains. 
Mr W. Carruthurs, the distinguished fossil botanist, also 
states in the same work for May, 1885, that he has observed 
some roots of palms in the Avebury stones, but they are gene- 
rally unfossiliferous, and contain some flint pebbles and stones 
only slightly rolled. Sarsens are used extensively for building 
purposes, as may be seen in the Parish Church and other build- 
ings in the neighbourhood; part of Windsor Castle is also built 
of them. 
Mr Ernest Sibree, of the Indian Institute, Oxford, was 
one of the party, and when on Silbury some discussion took 
place with him, the President, and the Vice-President (Mr 
John Bellows) as to the history of the hill and Avebury, and 
the President requested Mr Sibree to supply him with a few 
remarks on the subject. There is so much difference of opinion 
among Archeologists that any new light is gladly welcomed, 
and I thankfully introduce Mr Sibree’s notes— 
“NOTES ON AVEBURY AND SILBURY 
“The name Avebury is probably connected with Avington, the name of 
a village lower down the Kennet, Av or Ave being possibly an ancient word 
