349 
some liad been produced by the earth and others by the sea. 
He says, “ Only some make mention of inundations, and I 
know not what immemorial course of ages ; though they do 
that overly, and as Twere by the by.” Steno himself gives 
as good an account of the matter as could be desired. Speak- 
ing of “ cockles/"’ he says, “ Where the penetrating force of 
juices hath dissolved the substance of the shell, the same juices 
being either drunk up by the earth, have left the spaces of 
shells void (which I call aerial shells), or being altered by new 
adventitious matter, have, according to the variety of that 
matter, filled up the spaces of the shells, either with crystal, 
or marble, or stone. Whence comes that very pretty marble, 
called Nepheri, which is nothing else but a sediment of the 
sea full of all sorts of shells, where the substance of the 
shells being wasted, a stony substance is come in the place 
thereof/'’ 
But Steno wrote not only of objects found in the rocky 
beds of the earth, but of the beds, or strata, themselves. In 
a notable passage on this part of the subject, he says : “At 
the time that any bed was formed, there was another body 
under the same bed, which did hinder the further descent of 
that dusty [muddy?] matter/"’ Again, “At what time there was 
formed one of the upper beds, the lower bed had attained a solid 
consistency/"’ So he reasons as to the succession and super- 
position of strata. Then he saj^s, “ ■’Tis certain that when any 
bed was formed, its inferior surface and that of its sides did 
answer to the inferior body and of the bodies lateral, but the 
superior surface was, as far as possible, parallel to the horizon. 
So that all the beds, except the lowest, were contained in two 
planes, parallel to the horizon. Hence it follows that beds, 
either perpendicular to the horizon, or inclined to it, have 
been at another time parallel to the same.” He then speaks 
of the “beds” changing their places, “'first, by a violent 
excussion of the beds upwards.” “ The other is by the falling 
down of the upper beds, when the lower matter or foundation 
being’ thrown down, the upper bodies begin to crack; whence, 
according to the variety of cavities and crevices, there follows 
a various situation of the broken beds.” So he says, “ This 
changed situation of beds affords an easy explanation of many 
things else difficult enough to give an account of.”* The for- 
mation of strata, the inclosure of fossils, the change of the 
position of strata, the forces at work in producing these effects, 
the conditions necessary to the operation of these forces, and 
the consequent result in the external form of the earth, as 
* Steno, pp. 42, 43. and 99. 
