90 Proceedings of the Royal Physical Society. 



air and the centrifugal force causes the net to expand like a 

 flat old-fashioned umbrella, in which shape it reaches the 

 surface of the water. The weight of the bullets causes the 

 descent of the circumference, and the net assumes an oval 

 form, and the tiny fish are caught by the meshes in their 

 attempt to escape. 



Mr Bryson also took the opportunity of reading the following 

 note he had received from his friend Dr James M'Bain, R.N. : — 



"As an additional instance of the tenacity of life in cer- 

 tain species of the mollusca, I may mention that in the 

 spring of 1857 a small Helix was picked out from amongst 

 some dried raisins, and handed over to me by one of my fa- 

 mily. As it had the thin, transparent, glistening film cover- 

 ing the aperture, it occurred to me to repeat the experiment 

 related by Dr Baird, in reference to the Egyptian desert snail 

 in the British Museum, and included in the examples of 

 tenacity of life in these animals given by Mr Woodward in 

 his ' Manual of the Mollusca.' The following day our shy 

 friend made his appearance in the glass vessel, and lived with 

 us for five months. It was occasionally supplied with a little 

 water, and portions of green vegetables, such as cabbage and 

 lettuce, and seemed to give a preference to the latter. It was 

 precisely identical with specimens of Helix virgata got at 

 Shotover Hill, near Oxford, along with our friend Dr Mel- 

 ville in 1847. This species is widely spread over the south of 

 Europe, and, although having no objection to the interior, 

 yet, like ourselves, has also a strong attachment for the neigh- 

 bourhood of the sea. It is not surprising, therefore, to find it 

 in company with Malaga raisins ; but those singular excep- 

 tions to the general laws, in the marked examples of torpidity 

 in various animals, living for indefinite periods without food, 

 and almost without air, are surprising." 



