Biographical Notice of Edward Forbes. 379 
mineral character, the sea bottom not being equally variable in 
each, and becoming more and more uniform as we descend. 
Again, the deeper zones are greater in extent, so that whilst 
geographical distribution. 
But these eight regions are themselves the scene of incessant 
change; not only are the depths modified by the addition of fresh 
matter, but the very animals themselves, by their own increase, 
so modify the nature of the sea bottom as to render it unfit for 
their own existence, until a new layer of sedimentary matter, un- 
charged with living organic contents, has formed a fresh soil for 
similar or other animals to thrive on. It is impossible to overlook 
the importance of these observations in explaining many of the 
daily recurring phenomena which are brought under the notice of 
the geologist ; in the last observation we may see an explanation 
f the phenomenon of interstratification of fossiliferous and non- 
fossiliferous beds. 
[ must refer you to the report itself for an account of the phe- 
nomena which would be presented to us were the bottom of the 
Mgean Sea to be elevated and converted into dry land, or to be 
filled up by a long series of sedimentary epositions. He con- 
cludes by observing that, “supposing such an elevation to have 
taken place, a knowledge of the association of species in the re- 
gions of dept 
of the depth of water in which each bed was deposited, A be 
bled, by a careful examination of the successive overlying groups 
of species, to ascertain whether in any given locality brought un- 
der his notice, the sea bottom was being elevated or depressed.” 
But I have already dwelt too long on this report; I must has- 
ten to other scenes in the life of Edward Forbes. During his 
