SOME POINTS IN THE HISTOEY OF THE 

 OEMER (haliotis tuberculata). 



BY MR. HERBERT FLEURE, B.SC. 



The ultimate aim of the scientific naturalist is to elucidate 

 the problem " How what is has come to be what it is," and 

 though the solution will never be complete, great steps towards 

 that ideal have been taken, among which one of the greatest 

 was Darwin's production of the " Origin of Species " in 1859. 

 Since then all the biological students' endeavours have aimed 

 at reconstructing the past history of the world of life, a history 

 which, in the case of every type, must be the account of a long 

 course of variations in structure, which have accumulated 

 because they helped the animal in its struggle for existence, or 

 helped it to leave numerous or well developed offspring. 



In studying the history of the Ormer we must first know a 

 little of its relations, and these, including the limpet, the 

 Trochus or Top-shell, the periwinkles and snails, and many 

 other types, form with it the well-known animal group of the 

 Gastropoda — that is, speaking from the evolutionary point of 

 view, we may call them the twigs of the Gastropod branch of 

 the great genealogical tree of the animal kingdom. Their 

 complete history would start with a description of this 

 " branch " from which the twigs have sprung — in other words 

 Avith an account of the last common ancestor of the whole 

 group, and would thence trace the adaptations to special 

 circumstances which have led to the appearance of the various 

 distinct types. This ancestral form lived, however, in those 

 very early days when the Cambrian rocks were beginning to be 

 laid down, perhaps,according to moderate estimates, 60,000,000 

 years ago. It is, therefore, only by more or less probable 

 speculation that we can trace the earlier part of this history. 



Fortunately for our purpose, a few twigs still survive 

 which budded not far from the base of the branch ; we still 

 have, to use the ordinary phrase, a few very archaic Gastro- 



