198 THE RATE OF GROWTH [ch. 



Plaice caught in a certain area, March 1907 and December 1905. 

 Variation of k, the weight-length coefficient, with size 



These weights and measurements of plaice are taken from the Department of 

 Agriculture and Fisheries' Plaice-Report, i, pp. 65, 107, 1908; ii, p. 92, 1909. 



Japanese goldfish* are exposed to a much wider range of tem- 

 perature than our plaice are called on to endure ; they hibernate in 

 winter and feed greedily in the heat of summer. Their weight is 

 low in winter but rises in early spring, it falls as low as ever at the 

 height of the spawning season in the month of May; so for one 

 weight-length fluctuation which the plaice has, the goldfish has a 

 twofold cycle in the year. The index reaches its second and higher 

 maximum in August, and falls thereafter till the end of the year. 

 That it should begin to fall so soon, and fall so quickly, merely means 

 that late autumn is a time of groipth ; the fish are not losing weight, 

 but growing longer f. 



* Cf. Kichiro Sasaki, Tohoku Soi. Reports (4), i, pp. 239-260, 1926. 



t Much has been written on the weight-length index in fishes. See (int. al.) 

 A. Meek, The growth of flatfish, Northumberland Sea Fisheries Ctee, 1905, p. 58; 

 W, J. Crozier, Correlations of weight, length, etc, in the weakfish, Cynoscion 



