180 HALF AN HOUR WITH SHELL-FISH. 



XI. 



HALF AN HOUR WITH SHELL -FISH (UNIVALVES). 



PERHAPS no objects are so eagerly sought after, 

 or so much admired, at the sea-side, as shells. 

 They are pretty enough to be thought worthy of 

 transference, for even the commonest has an interest 

 transcending that of other creatures. How was it 

 possible for animals so lowly organised, with no 

 evident architectural means for the purpose, to build 

 up mechanically regular dwelling-places like these ? 

 Science teaches us that beneath the most familiar 

 appearances there often lurk lessons of profoundest 

 wisdom. It is only ignorance that sneers at a 

 pursuit because it deals with commonplace objects. 

 Nay, the scientific man is aware that the more he 

 enters into the structural details of the lowliest 

 creature, the more numerous are the practical lessons 

 he is likely to learn ! 



The law which regulates even such an apparently 

 trivial matter as the mode in which the shells of 

 univalves twist or turn, is as mathematically true as 

 the conic sections we find entering into the orbits of 

 planets and comets. Mr. Moseley has shown that 

 the size of the whorls, and the distance between 

 contiguous whorls, in such shells as the common 

 Wentle-trap (Turritetta communis) of our shores, 



