28 ANIMAL INTELLIGENCE. 



roborative case, the improbability of the snail remembering 

 for twenty-four hours the position of its mate is very 

 much reduced ; while the subsequent communication, if 

 it took place, would only require to have been of the 

 nature of * follow me,' which, as we shall repeatedly find, 

 is a degree of communicative ability which many inverte- 

 brated animals possess. Therefore, in view of these con- 

 siderations, I incline to Mr. Darwin's opinion that the facts 

 can only be explained by supposing them due to intelli- 

 gence on the part of the snails. Thus considered, these 

 facts are no doubt very remarkable ; for they would appear 

 to indicate not merely accurate memory of direction and 

 locality for twenty-four hours, but also no small degree of 

 something akin to ' permanent attachment,' and sympa- 

 thetic desire that another should share in the good things 

 which one has found. 1 



The case to which I have just alluded as proving 

 beyond all doubt that some Gasteropoda are able to retain 

 a very precise and accurate memory of locality, is that of 

 the common limpet. 



Mr. J. Clarke Hawkshaw publishes in the Journal of 

 the Linnaean Society the following account of the habits 

 in question : 



The holes in the chalk in which the limpets are often to be 

 found are, I believe, excavated in a great measure by rasping 

 from the lingual teeth, though I doubt whether the object is to 

 form a cavity to shelter in, though the cavities, when formed, 

 may be of use for that purpose. It must be of the greatest im- 

 portance to a limpet that, in order that it may insure a firm 

 adherence to the rock, its shell should fit the rock accurately ; 

 when the shell does fit the rock accurately, a small amount of 

 muscular contraction of the animal would cause the shell to ad- 

 here so firmly to a smooth surface as to be practically im- 

 moveable without fracture. As the shells cannot be adapted 

 daily to different forms of surface, the limpets generally return 

 to the same place of attachment. I am sure this is the case 

 with many ; for I found shells perfectly adjusted to the uneven 

 surfaces of flints, the growth of the shells being in some parts 



1 The facts, however, in order to sustain such conclusions, of course 

 require corroboration, and it is therefore to be regretted that Mr. Lons- 

 dale did not experimentally repeat the conditions. 



