of the Fishery Board for Scotland. 



297 



herrings. To obviate as far as possible the risk of confusion, he measured 

 only the smaller herrings at the various periods (the numbers are not 

 stated) with the following results . — 





Mm. 



Inches. 



Increase. 









Mm. 



14th November 1876, 



84 







End of November 1876, 



90 



3 T 9 r 



6 



,, December 1876, ... 



100 





10 



,, January 1877, 



110 





10 



,, February ,, 



114 





4 



,, March ,, 



135 



a, 



21 



,, April ,, 



138 













54 



Thus, the total growth in about 167 days, over the winter, according 

 to these observations, was approximately 54mm. (2-J- inches), or at the 

 rate of *32mm per day, or about 9-6mm. per month; that is to say, at 

 about the same rate as the average growth of the smaller forms in the 

 height of summer. 



This does not agree with my experience as to the growth of other 

 fishes, in which growth is much retarded or completely arrested, it 

 may be, in winter, and which grow fastest in the younger stages. 



Some experiments were made by keeping herrings in confinement. 

 Two, taken on 12th August among a lot which measured from 50mm. 

 to 55mm., were respectively 106mm. and 96ram. 4| months later. The 

 growth thus amounted to about 48mm., or about 10"7mm. per month. 



Three of a medium size of 75mm. on the 24th October, kept in an 

 aquarium, measured 100mm. on 28th December, 65 days later, or an 

 increment of nearly a 4mm per day ; at the end of January they measured 

 110 mm. (an increase at the rate of almost 'Smm. daily), the total 

 increase in a little over three months being 35mm., or approximately 

 11mm. per month. 



Meyer concluded that the spring herring of the western part of the 

 Baltic reach a length of from 130mm. to 140mm. (5J-5J inches) at the end 

 of their first year j that a month after the fertilisation of the eggs the 

 mass of larvae, in water over 12°C. (53'6°F.), measure from 17mm. to 

 18mm. ; in two months, from 34mm. to 36mm., and in three months from 

 45mm. to 50mm., growth thereafter for the remaiming months of the 

 twelve being approximately at a similar rate of 10mm. or 11mm. per 

 month. 



Ripe herrings, both spring and autumn, were found at 20cm. (7J 

 inches) ; these were the smallest, more commonly the size at first- 

 maturity was 210mm. to 220mm. (8| to 8| inches), and he states that they 

 are got in the Baltic from 160mm. to 200mm. His conclusion is that the 

 herring does not reach sexual maturity before the end of the second year, 

 but this conclusion is pieced together from various considerations that 

 appeared to him probable, and was not attained by direct evidence. 



A few years later, Meyer made a number of observations on the 

 growth of young herrings from artificially fertilised eggs (15a). The 

 eggs were fertilised on 26th April, and before hatching they were placed 

 in a wooden vat supplied with fresh supplies of water daily. Hatching 

 occurred in from 14 to 15 days, the temperature being 518° to 53*6°F.; 

 later in the summer the temperature of the water was about 68 C F. 

 After a few days some showed a considerable increase in size, measuring 



