LIFE-HISTORY OF AMPHIGONOPTERUS AURORA. 



207 



(1914, pp. 61-71) has induced an important generalization, the 

 lazv of groivth compensation. Those salmon which grow most 

 in their first year (as a result of earliest hatching or of other 

 causes), tend on the average to grow least in their succeeding 

 years, while those which have attained a relatively small size at 

 the end of the first year, grow with accelerated speed during the 

 next years. The physiological mechanism of the salmon appears 

 to regulate its growth in such a fashion that the length of the 

 adult fishes of each race varies but little. It was hoped that it 

 might be determined whether this law of growth applies to Am- 

 phigonoptcrus, but so few fishes more than one year of age were 

 examined, that the data are incomplete. The evidence being 

 suggestive, however, is presented in the following table (based 

 upon the material from Piedras Blancas). 



TABLE VIII. 



COMPUTED LENGTHS OF TWENTY 3- TO 6-YEAR-OLD FEMALES OF AMPHIGOXOP- 



TERUS AT THE END OF FlRST THREE WINTERS. 



It appears probable that the variation in size of Amphigonop- 

 tcms at the end of the third winter is less than at the end of the 



