200 ON THE GROWTH OF 
Took the lobes of roe, containing ova on the 
point of being deposited, from a Salmon weighing 
sixteen pounds, which was captured on the 26th of 
November, 1847, and found their weight to be four 
pounds. 
From these instances it is apparent that the weight 
of Salmon and Sewin may be diminished one fourth 
by the emission of their ova alone, the weight of the 
collapsed ovaries with their included germs being too 
insignificant to be taken into consideration ; and if to 
this cause of decreased ponderosity be added another, 
namely, deterioration in condition during the sojourn 
of these species in fresh water, the absolute loss in 
weight may be estimated at one third or more—a cir- 
cumstance which ought on no account to be over- 
looked in attempts to determine their rate of growth 
by marking individuals; and this remark applies 
with peculiar force when the subjects selected for ex- 
periment are kelts, as, unfortunately, it is too com- 
monly the practice to omit measurement altogether 
on such occasions, and merely to give a statement 
of weight, which, unaccompanied by other data, is 
evidently insufficient to decide the point in question. 
It appears then, from the physiological facts de- 
tailed above, that the growth of Salmon and Sewin 
during their first visit to the sea is much less rapid 
than it is commonly supposed to be; and as in the 
shoals of these species, which are more abundant in 
the Conway than any of the other migratory Salmo- 
