and water, and the consequent deficiency of insect food, their
dimensions are scarcely greater than at the end of the preceding
October: that is, they measure in length little more than three
inches.--(N.B. The old belief was that they grew nine inches in about
three weeks, and as suddenly sought the turmoil of the sea.) They
increase, however in size as the summer advances, and are then the
declared and admitted parr of anglers and other men.

3dly, Simultaneously with the two preceding broods, our rivers are
inhabited during March and April by parr which have completed their
second year. These measure six or seven inches in length, and in the
months of April and May they assume the fine silvery aspect which
characterizes their migratory condition,--in other words, they are
converted into smolts, (the admitted fry of salmon,) and immediately
make their way towards the sea.

Now, the fundamental error which pervaded the views of previous
observers of the subject, consisted in the sudden sequence which they
chose to establish between the hatching of the ova in early spring, and
the speedy appearance of the acknowledged salmon-fry in their lustrous
dress of blue and silver. Observing, in the first place, the hatching of
the ova, and, erelong, the seaward migration of the smolts, they
imagined these two facts to take place in the relation of immediate or
connected succession; whereas they had no more to do with each other
than an infant in the nursery has to do with his elder, though not very
ancient, brother, who may be going to school. The rapidity with which
the two-year-old parr are converted into smolts, and the timid habits of
the new-hatched fry, which render them almost entirely invisible during
the first few months of their existence,--these two circumstances
combined, have no doubt induced the erroneous belief that the silvery
smolts were the actual produce of the very season in which they are
first observed in their migratory dress: that is, that they were only a
few weeks old, instead of being upwards of two years. It is certainly
singular, however, that no enquirer of the old school should have ever
bethought himself of the mysterious fate of the two-year-old parr,
(supposing them not to be young salmon,) none of which, of course, are
visible after the smolts have taken their departure to the sea. If the
two fish, it may be asked, are not identical, how does it happen that
the one so constantly disappears al