NATUEAL HISTOKY OF THE SALMON. 51 



A small difficulty or doubt, however, affecting the 

 half-and-half, theory, remains even after we have accepted 

 as decisive all that the ponds have told us. Though we 

 know that some of the year-olds left the ponds for the 

 river, we do not know that they left the river for 

 the sea. Placed between the conflicting assertions of the 

 two parties, the inquirer may naturally ask. Had the 

 young fish that left the ponds, after the close of their 

 first year, the migratory dress and habits, or had they 

 not ? For if they had, their departure was obviously a 

 regular process of nature ; if they had not, their leaving 

 the pond would not be sufficient evidence of their inten- 

 tion then to proceed to the sea. Here, unfortunately, 

 the accounts of the first and best known experiment 

 were somewhat conflicting. On the 2d May 1855 (i.e. 

 when, on the one-year hypothesis, the time of migra- 

 tion had arrived), the fish in the ponds were examined 

 by a highly competent committee, iacluding Lord Mans- 

 field and the late Mr. James Wilson the naturafist, and 

 the decision was that they were not ready to descend. 

 But on the 19 th of the same month, there was a meeting 

 of a portion of the committee, at which it was agreed 

 that the fish were ready to descend. The grounds on 

 which this latter conclusion was come to, do not appear 

 to us to have sufficient extent or certainty. The prin- 

 cipal fact mentioned is, that twelve of the fish were 

 taken by the rod, and that, out of these, five were, ac- 

 cording to the judgment of the persons present, in a 

 migratory condition. These seem rather slender data on 

 which to arrive at and. put in force so large a conclusion, 

 especially as even Mr. Shaw had stated that he had 



