NATURA1> HYDRAULIC INSTRUMENTS. 381 
These beautiful arrangements are, and ever 
have been, subservient to a common object, viz. 
^he construction of hydraulic instruments of es- 
^^ntial importance in tlie economy of creatures 
destined to move sometimes at the bottom, and 
otlier times upon or near the surface of the 
The delicate adjustments whereby the same 
principle is extended through so many grades 
^iid modifications of a single type, show tlie 
unifoimi and constant agency of some control- 
h'lg Intelligence ; and in searching for the origin 
so much method and regularity amidst variety, 
^he mind can only rest, when it has passed back, 
through the subordinate series of Second causes, 
to that great First Cause, which is found in the 
'^'dl and power of a common Creator. 
SECTION VIII. 
FORAMINATED POLYTIIALAMOUS SHELLS. 
Nummulites. 
the present were a fit occasion for such minute 
'iiquiries, the investigations of the various known 
Species of Microscopic shells would unfold a 
Tories of contrivances having relation to the eco- 
iioiny of the minute Cephalopods by which they 
'^ore constructed, not less striking than those we 
been examining in the shells of extinct 
