It is supposed by some writers that the salmon makes two voyages in each year to the sea, and this is quite possible, as we may judge from the data already given on this point; but sometimes the salmon, although it can swim with great rapidity, takes many weeks to accomplish its journey because of the state of the river. If there is not sufficient water to flood the course, the fish have to remain in the various pools they may reach till the state of the water admits of their proceeding on their journey either to or from the sea. The salmon, like all other fish, is faithful to its old haunts; and it is known, in cases where more than one salmon-stream falls into the same firth, that the fish of one stream will not enter another, and where the stream has various tributaries suitable for breeding purposes, the fish breeding in a particular tributary invariably return to it. But, in reference to the idea of a double visit to the salt water, may we not ask—particularly as we have the dates of the marked fish for our guidance—what a salmon that is known to be only five weeks away on its sea visit does with itself the rest of the year? A salmon, for instance, spawning about “the den of Airlie,” on the Isla, some way beyond Perth, has not to make a very long journey before it reaches the salt water, and travelling at a rapid rate would soon accomplish it; but supposing the fish took forty days for its passage there and back, and allowing a period of six weeks for spawning and rest, there are still many months of its annual life unaccounted for. It cannot, according to the ideas of some writers, remain in the river forty-seven weeks, because it would become so low in condition from the want of a proper supply of nourishing food that it would die. It is this fact that has led to the supposition of a double journey to the sea. The Rev. Dugald Williamson, who wrote a pamphlet on this subject, entertains no doubt about the double journey. “Salmon migrate twice in the course of the year, and the instinct which drives them from the sea in summer impels them to the sea in spring. Let the vernal direction of the propensity be opposed, let a salmon be seized as it descends and confined in a fresh-water pond or lake, and what is its fate? Before preparing to quit the river it had suffered severely in strength, bulk, and general health, and, imprisoned in an atmosphere which had become unwholesome, it soon begins to languish, and in the course of the season expires: the experiment has been tried, and the result is well known. This being an ascertained and unquestionable fact, is it a violent or unfair inference that a similar result obtains in the case of those salmon that are forced back, from whatever cause, to the sea, that the salt-water element is as fatal to the pregnant fish of autumn as the fresh-water element is to the spent fish in spring?... If there is any truth in these conjectures, they suggest