Little Limps for Large Limpets. 327 



round the limpets very closely. It was noticed that 

 there was always a little bare space on one or other 

 side of the shell. In these cases the animal, after 

 being out to feed, was always found back close to the 

 drop wire, as if endeavouring to get back to the exact 

 spot it had left." 



Since, however, limpets are sometimes found in 

 situations from which it is impossible for them to make 

 excursions, Robertson devised another experiment : 



"To test," he says, "whether an adult limpet 

 subjected to confinement could live for any length of 

 time, on August 20 I drilled a circle of holes in the 

 rock round two well-grown limpets that were close 

 together, and inserted wooden pegs so near each 

 other that the animals could not get out. As I had 

 to leave, my friend Mr. Cook, Millport, visited them 

 occasionally and found them all right till December 

 20, when it was found that one of the pegs had given 

 way and one of the limpets had made its escape to 

 a little distance ; but the other was all right within 

 its enclosure, having subsisted within a space of not 

 more than a quarter of an inch beyond its shell for 

 124 days." 



The limpet has a tongue which when stretched out 

 is about double the length of the shell, and this tongue 

 is furnished with rows upon rows of strong, curved teeth, 

 forming a very beautiful object under the microscope. 



all the known living species, and two thin quartos on the extinct species. 

 I do not doubt that Sir E. Lytton Bulwer had me in his mind when he 

 introduced in one of his novels a Professor Long, who had written two 

 huge volumes on limpets." It must not be supposed from this that 

 Lytton Bulwer confounded limpets with cirripedes. He was bound to 

 disguise his professor to some extent. 



