HOW ANIMALS ADAPT THEMSELVES 



Similar observations were made at an earlier 

 date, by Mr. George Roberts, at Lyme Regis. 



Let us now take an instance of adaptation in 

 form. And this time we will take a shell so com- 

 mon that everybody will know it. 



Everyone who has spent a little time in nat- 

 uralising on the shore, has noticed how often you 

 may find univalve shells, such as those of the 

 whelk and periwinkle, with the top of the shell 

 knocked off. This is nearly always the case with 

 the dead shells that you find strewn along the 

 tide-line ; and after a storm, on a rocky coast, 

 you may find shells that still contain the living 

 tenant, in the same sad condition. And you may 

 also meet not infrequently with shells, dead or 

 living, that bear evidence of the owners' efforts 

 to repair them after an accident to the spire. A 

 piece has been broken, and you find it cemented 

 on again by a patch of shell, serviceable no doubt 

 to the owner, but crooked and unsightly in ap- 

 pearance. Now there is a very common shell, 

 the little yellow periwinkle, which has practically 

 done away with its spire, the coils of the shell 

 being so curved that the earlier part of the spire 



