296 Part II].—Twenty-fourth Annual Report 
but the great bulk of them had at this time a length of 25mm. to 
28mm. (1-13 inches) ; they could not be older than three months, showing 
a rate of growth of at least 13mm. a month, while the majority could 
scarcely be older than six weeks. By the end of July they were trans- 
formed, and then measured 45mm. to 55mm. (12-2 ,°, inches). 
It is important in considering these results to note the temperature 
prevailing in the locality, and I append here a table compiled from those 
in Meyer’s paper, for the ten months given ; up to and including July 
they refer to Schliewasser, and are the mean of three years, 1875-77 ; 
for the rest they refer to Kiel Bay and are the mean of two years, 
1875-76. They are all surface temperatures, and are tn F. 
Mean. Maximum. | Minimum. 
March, .. a; 35°6 41:9 32:0 
April, .. we, 44:2 50:0 39:2 
Maye «4. 2 | 51:2 57:2 42°8 
June.) .v. uit 62-2 109 51-8: 
Jaly, of css tas 66:2 (2:3 57-2 
August, ra 67°1 (ei 58°1 
September, .. | 61:5 66°9 52°D 
October, fs 54:5 59°7 44-2 
November, .. | 43°3 50:7 34:9 
December, aera| 36:9 44-2 32:9 
On 11th June, 1874, Meyer put into a floating box at Kiel a number 
(not stated) of transparent post-larval herrings, measuring 25mm, to 
28mm., the growth of which is shown as follows :— 
Date. No. of Days. | Length. Increase. Gadi ee bean 
Mm. Mm. Mm. 
June 24, 13 31-83 4-7 “42 
July 6, 25 (12) 37-38 5-6 46 
an alle 40 (15) 41-43 4-8 “30 
August 1, 50 (10) 45-46 3-4 "BD 
The transformation of these spring herrings was completed when they 
were 41mm. long; and the total growth in the 50 days was about 
15mm. to 17mm. (3-14 of an inch), or about 10mm. a month. 
This experiment was a good one, and it would have been improved if 
the numbers at the different sizes had been noted. It will be seen that 
growth became somewhat slower towards the end of the experiment. A 
growth of about 10mm (2 of an inch) per month at this period, and with 
high temperatures prevailing, is not perhaps excessive. 
At the end of August and beginning of September, Meyer also 
measured the young herrings in the neighbouring bays, after they had 
left the mouth of the Schlei and were mixed with other and larger 
