306 Part III.—Twenty-fourth Annual Report 
The difference referred to may be brought out by the following 
diagram, showing in proper relation the annual growth of the long rough 
dab and whiting up to sexual maturity, and of the herring according to 
Meyer and Jenkins up to the same period. 
1 2 
I | I Herring (Meyer) 
1 2 3 
Il | | | Herring (Jenkins). 
1 2 
I J Whiting. 
1 2 3 
l I I I Long Rough Dab. 
Meyer’s methods of determining the size of the herrings living 
naturally in the sea were unsatisfactory, and were unlikely to furnish a 
just estimate of the average size or of the true rate of growth, and his 
experiments are subject to important reservations, since only selected 
results are given, and not full details or numbers; and, moreover, too 
much stress was laid on the amount of growth in the summer months as 
a factor in computing the amount of growth for the whole year. 
Thus, the growth of the herrings in the Schlei, as determined by him 
for comparison with his later rearing experiments, amounted to only 
48-54mm. (14-24 inches) over the five summer months, or an average of 
just 10mm. per month, and the herrings which he reared grew to a 
similar extent over the period. But the temperature in these months is 
the highest in the year, the means ranging from 51:2 F. for May to 67:2 
F. for August, and in no other month, except May, was it under 61°5 F. 
Then, again, in the best of his experiments, in which the young herrings 
were kept in a floating box for 50 days, the growth was at the mean rate 
of 96mm. (2 of an inch) per month, but the months were at the end of 
June and July, the mean temperature in the latter month being 66°2 F. 
Compare these reasonable results with his results in winter, derived 
from the comparison of herrings from the sea, as shown in another Table. 
We find that from the end of November to the end of March (when with 
many fishes growth is quite arrested and always very slow) the indicated 
growth in the four months, December to March, amounted to 48mm., or 
12mm. a month, which is higher than in summer, a result that is 
obviously fallacious. And yet the average size when a year old is placed 
at 135mm., a size which appears to have been inferred from five months’ 
growth at 10mm. per month and seven months’ growth at 12mm. per 
month. ; 
In point of fact, as shown in my various papers on the rate of growth 
of fishes, as in the one in the present report, growth in summer greatly 
exceeds the growth during the rest of the year, while it is extremely 
small in the period from October-November to February—March.* 
* Here are afew examples. The growth of young haddocks from 31st July to 10th 
September (41 days) amounted to 38°6mm., or ata rate of ‘94mm. per day, or 29mm. 
per month; from 31st July to the 18th October (79 days) they increased by 61:1mm., or 
at a rate of ‘77mm. per day, or about 24mm. per month ; over part of winter, from 28th 
November to 15th January (48 days) the increase was 3°7mm., or at a rate of ‘(O8mm. per 
day, or 24 per month. Another series increased by 286mm. in the 41 days from 24th 
July to 8rd September, the rate being ‘7mm. per day, or 21mm. per month. Over winter 
and spring another series increased in 164 days, from 18th December to 30th May, by 
33:9mm., or at a rate of 2mm. per day, or 6°4mm. per month, and the period included 
April and May, which is one of the most favourable months. 
With the’young whiting, whose habitat more nearly resembles that of the young herring, 
the retardation in winter and the rapid growth in summer are marked. From June to the 
middle of September one set of observations shows a growth of ‘hmm. per day, or 15‘8mm. 
