FOSSIL EYES OF TRILOBITES. 397 
example yet found in the fossil world, of the 
preservation of parts so delicate as the visual 
organs of animals that ceased to live many 
thousands, and perhaps millions of years ago. 
We must regard these organs with feelings of no 
ordinary kind, when we recollect that we have 
before us the identical instruments of vision, 
through which the light of heaven was admitted 
to the sensorium of some of the first created 
inhabitants of our planet. 
The discovery of such instruments in so per- 
fect a state of preservation, after having been 
buried for incalculable ages in the early strata 
of the Transition formation, is one of the most 
marvellous facts yet disclosed by geological re- 
searches; and the structure of these eyes supplies 
an argument, of high importance in connecting- 
together the extreme points of the animal crea- 
tion. An identity of mechanical arrangements, 
adapted to the construction of an optical instru- 
ment, precisely similar to that which forms the 
eyes of existing insects and Crustaceans, affords 
an example of agreement that seems utterly in- 
explicable without reference to the exercise of 
one and the same Intelligent Creative power. 
Professor Miiller and Mr. Straus* have ably 
and amply illustrated the arrangements, by which 
the eyes of Insects and Crustaceans are adapted 
* See Lib. Ent. Knowledge, v. 12. ; and Dr. Roget's Bridge- 
water Treatise, vol. ii. p. 486 et seq. and Fig. 422 — 428. 
