T ■ 



VOL. II.] Studies Among MoUiisJcs, 3^3 



we would expect to find great uniformity among the shells of each 

 genus, so that we could very readily assign them to the genus at 

 least to which they belonged in a natural system of classification. 

 But when we find two different genera moulding and forming shells 

 so nearly alike that we cannot separate them, or determine the 

 genus to which they belong without referring to some peculiarity of 

 the soft parts, we begin to wonder if we have not made some mis- 

 take in our interpretation of nature and her laws in this respect. 



We have a class of not very wise philosophers, who tell us about 

 free will in man, perhaps in our studies we have found a class of 

 animals which act independently of this generic impulse. Free in- 

 stinct in animals is about as consistent as free will in man, but I 

 must confess that I cannot conceive of any impulse,^ faculty or 

 function, in either man or animal, that exists or acts in any par- 

 ticular independently of law. ' Now if a strawberry plant should 

 bear blackberries, or a currant bush produce cherries, we would 

 look on with astonishment. If we are correct in our divisions of 

 .Kooo nriinials into genera, then, in principle, this is just what Helix 



■rvana is doine" bv constructing its shell identical in every 



Newbe 



particular with the shells of the genus Zonites, instead of forming 

 them like the shells of the genus Helix, to which the animal is said 



to belong. 



Neivbcrrvana shows some 



other peculiarities worth noting. So far as we know at present its 

 geographical range extends from Los Angeles south about two 

 hundred miles, and from the coast inland about forty miles, thus it 

 ranges over an area of about eight hundred square miles. 



Within this area at certain localities favorable to its existence 

 and development it is found quite abundant, and it is not considered 

 a rare shell. Notwithstanding its wide geographical range and its 

 abundance, it adheres with rigid tenacity to one unvarying form, 

 and its sculpturing or smooth surface is unbroken by a single inno- 

 vation of any kind. 



In our philosophy of climatic effects upon land shells, we had 

 always supposed that in a warm, dry and treeless region, where al- 

 most perpetual sunshine prevailed, such as prevails over the en- 

 tire area in which this shell is found, that we must look for 

 white, bleached and colorless land shells, and so nearly have the 

 land shells of other regions been supposed to conform to this 



