14 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



certainly cannot subsist on fuci, as generally sup- 

 posed, but must depend on the waves for a supjDly 

 of some other kind of food, possibly infusorial."* A 

 similar case once came under my notice, of a half- 

 grown limj)et that had got jammed between the 

 inequalities of two large stones. It obviously had 

 been there for a considerable time, as the shell had 

 grown into a triangular shape to conform to the 

 walls of its prison. This creature also must have 

 depended for sujDport on what the waves carried in 

 to it. 



To test whether an adult limpet subjected to 

 confinement could live for any length of time, on 

 the 20th August I drilled a circle of holes in the 

 rock round two well-growm 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 20tli De- 

 cember, ^vhen it was found that one of the pegs 

 had given ^vay 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, and how much longer it may 

 be able to endure prison life I may at another time 

 be able to record. 



To find how often in confinement the limpet 

 shifted its site, I placed a piece of perforated zinc 

 over the JFtr, letting down through the i)erfora.tions 

 a thin wire on each side of the limpet, so that if 

 the ^vires were disturbed, although the animal was 

 on the same spot as when last seen, this showed 

 that it had been moving. A small gummed ticket 

 was placed on the outside of the glass opposite the 

 animal, which indicated whether it had returned to 

 the same spot which it had left. Sometimes it 

 went to the right side, and sometimes to the left ; 

 and when it settled down on the bottom of the jar, 



* Brit. MoUusca, ii. 424. 



