io8 ARISTOTLE THE FIRST SCALE-READER 



attributed to him, of being the first writer to note, certainly 

 the first to point out, that its scales make possible a shrewd, 

 in the case of the murex an exact, computation of the age of 

 a fish. 



If from lack of the microscope he did not in all particulars 

 antedate, he certainly blazed the trail for the discovery of 

 scale-reading at the close of the eighteenth century by the 

 Dutch microscopist van Leeuwenhoek ^ and its rediscovery as 

 regards the carp in 1899 by Hoffbauer,2 the GadidcB and 

 PlenronectidcB in 1900-03 by J. Stuart Thomson, ^ and the 

 SalmonidcB about 1904 by H. W. Johnston and others.* 



He tells us in The Natural History, I. i,that "what the feather 

 is in a bird, the scale is in a fish ";inIII. ii,^ that " the scales 

 of fish become harder and thicker, and in those which are wasting 

 or aging, become still harder" ; in VIII. 30, that "the old fish 

 are distinguishable by the size " (note this !) " and the hardness 

 of their scales." ^ 



He then buttresses this discovery of annual growth of scale 

 by another fact resulting from his observation that " the 

 Murex hves for about six years, and the yearly increase is 

 indicated by a distinct interval in the spiral convolution of 

 the sheU," ' or as Bohn renders the words, " its annual increase 

 is seen in the divisions on the hehx of its shell." 



In Leeuwenhoek ^ we read that, in the examination by 



^ Select Works, vol. i. p. 69. London, 179S-1801. 



' " Die Altersbestimmung des Karpfen an seiner Schuppe," in the R. Jahres- 

 ber. des Schlesischen Fischerei-Vereins fur 1S99. 



^ "The periodic growth of Scales in Gadidae and Pleuronectidae as an 

 Index of Age," in the Jour^ial oj the Marine Biolog. Assoc. (1900-03). VI. 

 373-375- 



* Reports of Scottish Fishery Board, 1904, 1906, 1907. 



* Cf. Anim. Gen., V. 3. 



6 hrjKoL 5' ol yipovTis avrwv rip fxeyedei tuv \iniSwv Kal rrj (TKKtipoTTjTi. Professor 

 D'Arcy Thompson, in his translation, renders this sentence " the age of a scaly 

 fish maybe told by the size and hardness of the scales." It is most probable, 

 though not a certainty, from contextual reasons, from Aristotle's habit of 

 casually harking back, and from Phny in his translation of it {N. H., IX. 33) 

 applying it generally, that this sentence appUes to all fish, and not solely to 

 the Tunny. 



' V. 15. t; yap tropcpvpa irepl err) €{, Kol Kad' (Kacrrov tviavrhv <pavipa ianv ^ 

 aij^rjffis ro7s Siaar-nixatn ro'is iv Tcf, oarpaKif rris f\iKos. The translation above is 

 taken from Professor D'Arcy 'Thompson {ibid,), to whose kindness I owe the 

 following reference and much else in this chapter, Phny, IX. 60, makes the 

 Murex live seven years. 



* Select Works, I. 69, London, 179S-1S01. 



