1941] 
Antiquity of Social Insects 
107 
pleasure of speculating as to the circumstances and method 
by which the original comb became this fossil” (p. 51). 
Nevertheless, despite the fact that “the method by which a 
wasp nest might be preserved so as to resemble the fossil in 
question is very difficult to imagine” (p. 51), they accept 
my invitation and supply a probable version of the process. 
Their chief difficulty, although they admit they have not 
experimented with nests, is to see how it would be possible 
for a paper nest to retain its shape long enough to permit 
the mud and sand contents of the cells to become so hard as 
to retain its form after the disintegration of the paper walls. 
“The thin, soft walls between the cells would, in our opinion, 
inevitably disappear within a short time long before the 
foreign material could harden” (p. 51). 
Obviously I do not know whether the postulated original 
nest hung from a tree, rock, or other support, or was a sub- 
terranean structure. Neither have I any information as to 
its topographic location ; its proximity to a stream or other 
body of water ; nor the conditions at the site of entombment 
whether on land or in water. These are the “circumstances” 
I had in mind when inviting the reader of my paper to 
speculate. As to the difficulties alleged by Bequaert and 
Carpenter in imagining a method of fossilization, it may be 
pointed out that if the cells of a papery nest were quickly 
buried in fine mud and sand so that pressure would be equal 
in all directions there would be little likelihood under normal 
conditions for much distortion of the cells, and the paper 
walls could conceivably serve as partitions for a long time, 
particularly if the paper were first partly carbonized or 
lignitized, as would very likely be the case in a compara- 
tively short time. Something of this nature probably occurs 
during the fossilization of wood. Contrary to most state- 
ments in textbooks about “replacement atom by atom of 
carbon by silica,” silicification of wood is essentially a process 
of infiltration and deposition of silica in the cells, and only 
secondarily one of replacement. The delicate cell walls gen- 
erally remain carbonized as is shown by the fact that peels 
displaying the cellular structure as a deposit of carbon can 
be pulled from sections of the wood appropriately treated 
with hydrofluoric acid. Those who have seen fossil wood in 
which the minute details of anatomy are exquisitely pre- 
