34 



THE GEOLOGIST. 



the position in which a fossil is found tell its tale, and is not 

 without importance in the interpretation of the earth's history. 



When from the fragments of the past creations you have discerned 

 how to dispose the first faint lines of design, and by experience 

 have so learned to fit them together as to comprehend or exhibit 

 something of the beautiful tracery of those grand scenes in which 

 Geology abounds, — you will have learned something yet more of 

 the value of a fossil. 



On the shores of the sea the waves in reckless confusion cast 

 their spoils, — floating shells and wood, and the dead carcases of 

 animals are mixed with boulders and rocks, and like the beaches 

 and strands of to-day are the conglomerates and littoral deposits 

 of the past— fragmentary or massive, organic or mineral, all 

 in disorder, and contrasting with the deeper waters, where the 



LiGN. 2. Shells disposed by a current according to their forms. 



feeble currents roll gently along the smaller shells and relics and 

 carefully dispose them, with almost the regularity of a cemeteiy, in 

 one direction according to their fonns. True, under the influences 

 of motion and gravitation, as the magnet to the pole, do they all 

 point to the spot to which the current trends. Again, if in any of 

 the ancient rocks we find the shells disposed throughout the thick- 

 ness of the beds, at all levels, and in their normal manner — for all 

 living shells have a natural position in the mud or sand, their close 

 proximity not necessarily indicating immediate succession of depo- 

 sits, — what should we infer ? Shells do not rest mdiscriminately on 

 their hinges, nor their anterior nor posterior ends, but those with 

 syphons project those organs upwards through the tubes of their 

 burrows to inhale and exhale the aqueous fluid at once to them 



