THE TARPON 69 



togetlier but the lines of deinarkation between widely 

 spaced (relatively) and closely spaced rings is so indefi- 

 nite that annual growth for the first few years is more 

 of a guess than a positive determination. Working out 

 toward the periphery, after what appears to be the 6th 

 year, well defined lines can be seen which maj^ be both 

 annuli and spawning marks. 



"Although the scales of most species show a marked 

 difference in growth as between winter and summer, we 

 cannot be positive that each well defined crowded area of 

 rings on the tarpon scale marks a j^ear of growth. It is 

 possible that the closely situated rings, denoting slow 

 growth, may form at no definite season of the year or 

 more than one such mark may occur during the course of 

 a single year. These are factors that can be determined 

 only by the study of a large amount of data and scale ma- 

 terial, especially of the smaller fish. 



"Because of the uncertainty due to the meager knowl- 

 edge of tarpon scale reading, the ages given in this re- 

 port must be accepted as tentative." 

 I am advised that the determination of age by the structure 

 of the scales has not been established in the case of any warm 

 water non-hibernating fish. 



J. R. Norman, the Assistant Keeper, Department of Zoology 

 (Fishes), of the British Museum, the author of that interest- 

 ing book, ^'A History of Fishes", wrote me in part as fol- 

 lows: 



"I know of no reliable work on the scales of tropical 

 fishes, and personally view with suspicion any attempt to 

 determine the age of these fishes from their scales. In the 

 case of Salmonidae, the scale reading has been checked 

 by marking experiments and its value has been proved 

 up to the hilt, but I am quite certain that the method can- 

 not be applied indiscriminately to all fishes. Unless feed- 

 ing slows down in winter as in the salmon there would 

 be no 'check' in the growth of the scale, and, if such a 



