678 Fishes. 



The truth of this was rendered more manifest by the circumstance that several of the 

 frogs were caught in their descent by holding out hats for that purpose. They were 

 about the size of a horse-bean, and remarkably lively after their aerial but wingless 

 flight. The same phenomenon was observed in the immediate neighbourhood." — 

 Leeds Mercury. 



[This is one of the misstatements in Natural History which have obtained univer- 

 sal credit. I am continually receiving similar accounts, not only of frogs, but toads, 

 white fish and eels. May I request of correspondents, who are on the spot where these 

 facts are stated to occur, to enquire into them more narrowly ; and methinks it would 

 be no difficult matter to trace the presence of the animals to more natural sources than 

 the clouds. — E. Newman.'] 



Note on the Salmon. " Prof. Twiss next read a paper in illustration of a collection 

 of specimens of the ova and fry of the salmon, presented to the Ashmolean Museum, 

 by Mr. A. Young, the manager of the Duke of Sutherland's fisheries on the river Shin, 

 in Sutherlandshire. The collection consists of thirteen specimens of the ova, selected 

 at intervals varying from twenty to one hundred and thirty-three days from the time 

 of their being deposited ; and ten specimens of the young fry, from the day on which 

 they were hatched, the one hundred and thirty-fifth after impregnation, to the time 

 when they assume the silvery character of the smolt, and descend to the sea ; which in 

 this case was one year and nine days after exclusion from the egg. 



" The experiments of Mr. Young, which have now been carried on through a pe- 

 riod of three years, with the greatest care, confirm the previous observations of Mr. 

 Shaw, in the Nith river, in Dumfriesshire, in their general bearings, with such slight 

 variations as the different characters of the respective rivers may account for. 



" Mr. Young has ascertained that the average period required for hatching the ova 

 of the salmon of the Shin river, varies from one hundred to a hundred and forty days, 

 according to the greater or less warmth of the weather. Mr. Young considers that 

 the fish passes through the condition of par, whose characteristics are the transverse 

 bands, and assumes the silvery appearance of the smolt, in about twelve months from 

 the time of being hatched ; and he is disposed to think, that some of the young fish 

 which have been deposited as ova, and therefore hatched, late in the season, do not as- 

 sume the smolt appearance, or go down to the sea at the end of the first year. 



" Prof. Twiss called attention to the importance of these observations, in connex- 

 ion with the preservation of the young fish, which have hitherto not unfrequently been 

 taken and destroyed, as if a distinct species of trout : to the increased facility of pro- 

 pagating peculiar breeds or races of fish, by transporting the ova, when impregnated, 

 in water, from one river to another : and to the great value of careful notices as to the 

 spawning seasons of the fish of different rivers, in connexion with a more discriminat- 

 ing system of legal regulations, as to the fence months. 



" Dr. Buckland gave some account of his visit to the experimental ponds at Drum- 

 lanrig, in company with Prof. Agassiz, who was himself conducting a series of analo- 

 gous experiments on the trout of the lake of Neufchatel. He alluded to the great 

 probable advantages of hatching the ova in artificial ponds, with a view to the preser- 

 vation of the young fry. In the experiments of Agassiz and Sir F. Mackenzie, Bart., 

 it was found necessary to feed the young fry with the paunches of sheep." Athenoeum. 



