190 ON THE GROWTH OF 
Early in the month of June, Salmon in high con- 
dition, weighing three pounds and upwards, ‘ascend 
the Conway in considerable numbers if the state of 
the water be favourable; but that they cannot be 
identical with the Smolts of the same year is manifest, 
because the inversion of established physiological 
principles is involved in the opposite supposition ; 
for as great numbers of young Salmon weighing 
from half a pound to a pound come up the same 
river in August, full two months later than the 
former, there is no escaping from the unphilosophical 
conclusion to which such an hypothesis leads—namely, 
that young Salmon decrease in size as they increase 
in age. To avoid the awkwardness of this dilemma, 
it is only necessary to admit the identity of the small 
Salmon which ascend the Conway in August with 
Smolts of the preceding spring; and this view of 
the subject (which, if correct, completely subverts the 
theory of the all but preternatural growth of the 
Salmon in salt water) derives support from the gradual 
increase of this species in size when restricted to 
fresh water, and from some circumstances attending 
the loss of its teeth from the vomer. 
Adult Salmon of average dimensions are known 
to have one or two teeth only at the anterior ex- 
tremity of the vomer, though Smolts have the same 
part amply provided with teeth extending along a 
great portion of its length. In the summer of 1540 
I examined numerous specimens of Salmon in vari- 
