244, Mr. J. Blackwall on the Salmon and Bull-trout. 
On the 12th of November 1844, a salmon was captured 
weighing fifteen pounds, the weight of the lobes of roe, which 
contained a large quantity of ova in an advanced state of deve- 
lopment, being two pounds and three-quarters. 
A salmon captured on the 13th of November 1844 weighed 
seven pounds and a half, and the weight of the lobes of roe, 
which comprised ova almost in a fit state to be deposited, was 
two pounds. 
A bull-trout taken on the 18th of November 1844 weighed 
five pounds and a half, the weight of the lobes of roe, which 
contained ova in an advanced state of development, being one 
pound and a quarter. 
On the 11th of October 1847, a bull-trout weighing half a 
pound was captured, whose lobes of roe, comprising ova nearly 
ready for deposition, weighed two ounces. 
A salmon weighing fifteen pounds and a half was taken on the 
22nd of October 1847, and the lobes of roe, which contained ova 
in an advanced state of development, weighed three pounds. 
The lobes of roe, comprising highly developed ova, taken from 
a salmon weighing twenty pounds, which was captured on the 
10th of November 1847, weighed three pounds and fourteen 
ounces. 
Took the lobes of roe, containing ova on the point of bemg 
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 bull-trout may be diminished one-fourth by the emission of 
thei ova alone, the weight of the collapsed ovaries with their m- 
cluded germs being too insignificant to be taken into considera- 
tion; 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 circumstance which ought on 
no account to be overlooked in attempts to determine their rate 
of growth by marking individuals ; and this remark apples with 
peculiar force when the subjects selected for experiment are kelts, 
as, unfortunately, it is too commonly the practice to omit mea- 
surement 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. 
In drawing up this paper I have purposely avoided applying 
the Scotch term grilse to young salmon which have not spawned, 
as I entertain the opmion that few appellations employed by 
ichthyologists have been more abused or have led to greater con- 
fusion and misapprehension than this. 
