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,^ the Gadidce and 

 Pleuronedidce in 1900-03 by J. Stuart Thomson, 3 and the 

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



He tells us in The Natural History, 1. 1, that "what the feather 

 is in a bird, the scale is in a fish ";inIII. 11, ^ that " the scales 

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

 or aging, become still harder " ; in VIIL 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 lives for about six years, and the yearly increase is 

 indicated by a distinct interval in the spiral convolution of 

 the shell," ' 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, 1 798-1 801. 



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

 bey. des Schlesischen Fischerei-Vereins fur 1899. 



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

 Index of Age," in the Journal of the Marine Biolog. Assoc. (1900-03), VI. 



373-375- 



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



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



* S^Xot 5' ol yepoures avrwv rcfi fj-eyedei twv \€irlBa)v Kal Tp (rK\T]p6TriTi. 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 applies to all fish, and not solely to 

 the Tunny. 



' V. 15. ri yap irop(pvpa wepl €ttj 6|, Kal Kad' eKaarov iiiiavrhv (pavfpd fcrriv fj 

 aS^rjffis ro7s Siao'T'ij/tao-t rols iv t^ 6crrpdK({i ttjs tKiKos. 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. Pliny, IX. 60, makes the 

 Murex live seven years. 



® Select Works, I. 69, London, 1 798-1801, 



