Page:The Zoologist, 4th series, vol 6 (1902).djvu/189

Rh several Roach, 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 themselves 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 Roach 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?— (Brimstead Rectory, Stalham).

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 summer, 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 recognized 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