Young of Salmon and Migration of Eels. 305 



the form of the smelt begins to be assumed. I watched the survivors with 

 great attention for three weeks after, during which time the fins grew, and 

 the bag disappeared. At first they had no fins, but when they were about 

 a fortnight old, white specks appeared in the parts from whence the fins 

 grew, and in another fortnight the shape and membrane of the fins became 

 apparent. At the expiration of three weeks after the date of the portrait, 

 more than half of the fry had died, and I had their remains dried on a piece 

 of glass for the inspection of the society, but, unfortunately, the box contain- 

 ing them was lost. The remainder were set at liberty, and may possibly 

 be swimming about as grilse five or six pounds in weight, so wonderful is 

 the growth of this singular fish, and so insignificant its origin. 



Being upon the subject of fish, I may call the attention of the learned to 

 that curious fact, the migration of Eels. Sir Humphry Davy says, in his 

 Salmonia, " There are two migrations of eels, one from, and the other to 

 the sea ; the first in spring and summer, the second in autumn, or early in 

 winter. The first, of very small eels, which are sometimes not more than 

 two or two and half inches long ; the second, of large eels, which some- 

 times are three or four feet long, and weigh from ten to fifteen, or even 

 twenty pounds. There is great reason to believe that all eels found in 

 fresh water are the results of the first migration ; they appear in millions 

 in April and May, and sometimes continue to rise as late even as July and 

 the beginning of August." Sir Humphry Davy then proceeds to give ex- 

 amples of these migrations, the former of which, viz., the upward migration of 

 young eels in the spring, has long been noticed, by naturalists, with interest 

 and wonder. In the month of May, in the present year, I saw the advance 

 of a column of small eels in the River Erne, the extent of which seemed 

 infinite. For three or four miles that I walked down the river no diminu- 

 tion took place in the numbers, or change in the order of their march. 

 Where the stream was powerful, the column clung close to the banks, but 

 where they came to calm water, they spread out to a considerable extent 

 over the sandy bed of the river, still, however, urging their way up with 

 undiminished energy. The migration is sometimes continued for nearly a 

 week together, and the numbers that pass must be as the sands of the sea. 

 Whence have they come, and whither do they go ? The obscurity which 



