NOTES AND QUERIES. 151 



several Eoacb, a couple of Dace, a Gudgeon, and a small Pike — which 

 he had kept for nearly three weeks in a foot-bath standing under the drip 

 of a pump in his back yard. All the wells hereabouts are very shallow, 

 and so, susceptible to the influence of surface-water, which may account 

 for the longevity of these fish in pump- water. But the most curious thing 

 connected with them was this — when they were first put into the bath 

 (an unpainted galvanized one), they were all dark and brightly coloured ; 

 in about a week they began to lose colour, and so became much less 

 conspicuous. Here was a supposed case of fish assimilating them- 

 selves in tint to their surroundings — an instance of the assumption of 

 protective coloration ; for now, as seen from above, they were far less 

 conspicuous than when first put into the whitey-grey zinc bath., I 

 suggested that their loss of colour was due to loss of health caused by 

 the pump-water. A few days later, one of the Roach became blind, and 

 soon afterwards returned to its darker normal colour. It subsequently 

 died. On Feb. 12th I made another inspection, and found a second 

 Eoach partly blinded by a black fungoid growth on the eyes, and it also 

 was in process of turning back to its former dark hue. The question 

 arises, does light and exposure, acting through the eyes only, tend to 

 bring about a change of colour in fish ? — M. C. H. Bird (Brimstead 

 Rectory, Stalbam). 



MOLLUSC A. 



Duration of Life in Helix pomatia. — A few Edible Snails (Helix 

 pomatia) have been living here at large for at least seventeen years. 

 The first batch were brought from Normandy, and turned down in the 

 year 1882. Another lot from Surrey was added to the colony in 1884, 

 since which time no more have been introduced. They do not appear 

 to have bred, or, at any rate, I have seen no young ones, with the 

 exception of two broods reared in a greenhouse, and afterwards turned 

 out, and these soon disappeared, perhaps eaten by Thrushes, and 

 Hedgehogs. Yet a few adults have since appeared almost every sum- 

 mer, with a few exceptions, up to the last (1901), when two were seen. 

 They, or at least two or three of them, always keep to the same spot, 

 only a few yards square, and rarely wander any further from their 

 home. I believe that the two or three Snails just mentioned hibernate 

 under a heap of sticks, for it is close to this that they make their 

 appearance in summer. One venerable-looking Snail, easily recog- 

 nized by its bleached, weather-worn, and damaged shell, is very 

 regular in its annual appearance abroad. I have not seen any of 

 them moving about earlier in the year than May, or later than the 



