fry congregate.  According to the received doctrine, therefore, these animals were two of the migration of the preceding year; and thus it must necessarily follow that they remained in salt water, one ten, and the other eleven months, with an increase of growth so small as to be irreconcilable with the proof we have of the growth of the grilse and salmon during their residence in salt water.”—­P. 36.

We are not entirely of Mr Scrope’s opinion, that some salmon fry are descending to the sea during every month of the year; at least, we do not conceive that this forms a part of their regular rotation.  But the nature of the somewhat anomalous individuals alluded to by Mr Yarrell, may be better understood from the following considerations.  Although it is an undoubted fact that the great portion of parr descend together to the sea, as smolts, in May, by which time they have entered into their third year, yet it is also certain that a few, owing to some peculiarity in their natural constitution, do not migrate at that time, but continue in the rivers all summer.  As these have not obeyed the normal or ordinary law which regulates the movements of their kind, they make irregular migrations to the sea during the winter floods, and ascend the rivers during the spring months, some time before the descent of the two-year-olds.  We have killed parr of this description, measuring eight and nine inches, in the rivers in October, and we doubt not these form eventually the small, thin, rather ill-conditioned grilse which are occasionally taken in our rivers during early spring.  But it is midsummer before the regularly migrating smolts reappear as grilse.  However, certain points in relation to this branch of our subject may still be regarded as “open questions,” on which the Cabinet has not made up its mind, and may agree to differ.  Mr Scrope is certainly right in his belief, that, whatever be the range of time occupied by the descent of smolts towards the sea, they are not usually seen descending with their silvery coating on except in spring; although our Sutherland correspondent, to whom we have so frequently referred, is not of that opinion.  It may be, that those which do not join the general throng, migrate in a more sneaking sort of way during summer.  They are non-intrusionists, who have at first refused to sign the terms of the Convocation; but finding themselves eventually rather out of their element, on the wrong side of the cruive dyke, and not wishing to fall as fry into the cook’s hands, have sea-ceded some time after the disruption of their General Assembly.

Even those smolts which descend together in April and May, (the chief periods of migration,) do not agree in size.  Many are not half the length of others, although all have assumed the silvery coat.  “I had, last April,” Mr Young informs us in a letter of 3d June 1843, “upwards of fifty of them in a large bucket of water, for the purpose of careful and minute examination of size, &c., when