NATURAL HISTORY OF REDFISH, ETC., OF TEXAS 



187 



check on the scales than do fish secured from March to June, 1927 (the winter scale 

 check usually is formed by March 1). Obviously, a fish 2 years old in 1926 would 

 be 3 years old in 1927. 



Table 21, containing the averaged calculated lengths of 396 trout at the time 

 of the formation of the various winter checks, has two divisions — one presenting 

 the averaged calculated lengths of fish of all ages taken from April, 1926, to March 1, 

 1927, and the other (bottom of table), the averaged calculated lengths of trout taken 

 from March 1 to June 1, 1927. The latter group naturally show the additional 

 winter check formed during the winter of 1926-27. 



Table 21. 



-Averaged calculated total lengths of 396 spotted trout at formation of winter checks on the 



scales 



Inspection of this table reveals only slight differences in the various averaged 

 calculated lengths at the same ages for fish ranging from 1 to 8 years of age. The 

 decided absence of any "phenomenon of apparent change of growth rate" (such as 

 observed by Lee (1912) and other workers, in which, with increasing age, the age 

 classes of fish show a decreasing rate of growth in their calculated values for each 

 year of Hfe) is most noticeable. In fact, almost the reverse of Lee's phenomenon 

 appears to be the case, for the youngest fish (those in their second year with one 

 winter check) have the lowest calculated lengths (13.5 to 13.8 centimeters) for the 

 first winter, omitting the calculated length of 12.3 centimeters for three 9-year-old 

 fish. 



Table 22, giving a comparison between the averaged calculated lengths of trout 

 derived from measurements of two scales from the same fish, shows in a more distinct 

 manner than does Table 21 the trend of the younger year classes to possess smaller 

 calculated lengths than the older year classes. Averaging the two calculated lengths 

 for fish of the same age, it will be seen that the 1-year-olds have an averaged calcu- 

 lated length of 12.9 centimeters at the formation of the first winter check; the 2-year- 

 olds are 13.6 centimeters; the 3-year-olds are 14.9 centimeters; the 4-year-olds are 

 15.3 centimeters, and the 5-year-olds are 15.7 centimeters. A similar though 

 much less pronounced progression occurs for the second and fourth years' calculated 



