the Salmon, Herring, and Vendace. 471 



man. In this way, I believe a residence in fresh water to be de- 

 structive to the tape-worm in the salmon, and to remove from 

 him, or at least tend to remove from him, a cause of disease and 

 death. But I would not have it believed that I speak in this mat- 

 ter from any very extended opportunities for observation ; these 

 are difficult to be got, and entail infinite labour and great ex- 

 penses on the observer. And yet his sojourn in fresh water gives 

 rise to other evils, for it is then that a new parasite, the Lernaea, 

 fastens on his gills, organs of vital importance : to these latter, 

 sea water seems certainly to prove a poison *. We have experi- 

 mented also on the tape-worm when removed from the body of 

 the salmon, and found it speedily died with apparent pain, whe- 

 ther put into fresh river or sea water. 



SECTION IIL 



Many excellent observers have described, with more or less ac- 

 curacy, the generation of the salmon, the growth and progress of 

 the smolt, and the descent of the kelt or spawned fish to the 

 ocean ; but I know of no continued series of observations on the 

 subject, published by any one, of an authentic nature, and so as 

 to admit of no doubt. To remove this chasm, and to give to the 

 naturalist a nucleus whereon to build future observation, I have 

 thought it right to detail at considerable length the following 

 history of the Salmon Smolt, from its first deposition under the 



* The history of the tape-worm as it affects the human species, is a subject 

 well deserving a most extended inquiry. It is stated on the authority of Mr PE A EC E, 

 who travelled and resided a considerable time in Abyssinia, that the natives of that 

 country are exceedingly subject to tape-worm. After what I observed in Africa, 

 where the disease, on a particular occasion, attacked almost every one, I have no. 

 hesitation in ascribing the cause of its frequency in Abyssinia to the use of unwhole, 

 some beef. See a Memoir in the Edinburgh Medical and Surgical Journal for 

 J4J&2. 



