A HISTORY OF BERKSHIRE
was presented to Queen Victoria. A cast of it is to be seen in the Great Western Hotel at Reading. It is owing doubtless to a very plentiful fish diet, consisting largely of bleak, that the Thames trout attains such a large size. Every year fish of from 8 to 12 lb. are caught, and now and again some such monster as that already mentioned. In the Kennet it is interesting to notice how, as we pass up stream, we find the coarse fish gradually decreasing in numbers, while the trout become the more numerous but fall off in size. It is a reasonable inference that to obtain large trout it is desirable to have coarse fish in the river. Unfortunately when these big trout once become cannibals they are not often taken with the fly, except perhaps in the May-fly season, and where the fly is abundant. They are therefore of no great value to the fly-fisher. Many strains of trout have been placed in the Thames: fish for instance which had the trout of Loch Leven for ancestors, the excellent trout from the Wick, and many from the Surrey trout farm and other fish culture establishments. This intermixture of strains has been regretted by some, as it was feared that the quality of the Thames trout might be lowered by the introduction of this fresh but inferior blood. As a matter of fact however, ichthyologists and fish culturists now know that the size and condition of the trout depend more largely on the abundance of its food, and the extent and temperature of the water in which it dwells, than on ancestry. There is no doubt that, thanks to the restocking operations of the various fishery associations, trout are generally increasing in the Berkshire reaches of the Thames. The fish are not likely to increase naturally to any extent owing to the scarcity of suitable breeding grounds.
18. Rainbow Trout. Salmo irideus. Gibbons.
This is a comparatively new introduction to the Thames, and is still on its trial. It has however proved a great success in several ponds and larger enclosed pieces of water. In such places however it cannot breed, and therefore the stock has to be renewed from time to time.
19. Grayling. Thymallus vulgaris, Nilss.
The grayling, as already stated in our introductory remarks, does not appear to breed in the Thames, and only an occasional example is found which has strayed into it from the Pang or Kennet, or has been turned in by one of the fishery associations. Of late years the fish has been introduced into the Pang and has thriven wonderfully in this little trout stream. In the Kennet it thrives and increases still better, and at Hungerford a great many of these fish have been netted out from time to time to reduce their numbers. Within the last ten years grayling have been found in the lower reaches of the Lambourn, where presumably they have been turned in. The finest in the county are found in the Kennet.
APODES
20. Eel. Anguilla vulgaris, Turt.
This is a catadromous fish, i.e. one which descends the river to breed in the sea. The common eel is one of the most numerous of Berkshire fishes, and when we say common eel it should be understood that there is only one British freshwater eel known to ichthyologists. The various specimens which slightly differ in colour or in the shape of the nose are all or the same species, the differences being owing to sex, age and so forth. Those with pointed noses, commonly called silver eels, are the males, those with broad flat noses are the females. Eels are found descending the river from spring to winter, but their descent is greatest during the autumn floods. They are not found in the Thames and its tributaries in the same numbers as in former years, owing possibly to the pollution of the estuary. If the modern belief that they breed at great depths in the sea is correct, it is not obvious how the pollution of the estuary would interfere with them, unless it destroys the elvers on their ascent in the spring. Numbers of eels are caught in the Thames, Kennet and the Loddon by means of traps and baskets, and few on eel lines. The eels of the Kennet are justly celebrated and have been for centuries, in fact the fish of this remarkable stream are very much superior to those of the Thames and Loddon so far as condition and edible qualities go.
CYCLOSTOMES
21. Lampern. Petromyzon fluviatilis, Linn.
Lamperns used to be very numerous in the river, but have now become scarce above Teddington. Of late years very few lamperns have been recorded in the Thames on the borders of Berkshire, but Day mentions the capture of several in an eel basket near Surley Hall. Enormous quantities used to be captured in the Thames between Battersea and Taplow, over a million having been caught
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