CARPS. 



211 



were all taken from the same individual fish, and 

 their number might have been much increased. 

 The whole surface of each scale, when viewed 

 under a lens of low power, is seen to be covered 

 with concentric lines, following the irregular 

 sinuosities of the outline. These lines are the 

 edges of the successive layers of which the scale 

 is believed to be composed, each layer being 

 added in the process of growth to the under 



SCALES OF GOLD FISH {magnified). 



surface, and each being a little larger every way 

 than its predecessor; thus the scale is a very de- 

 pressed cone, of which the centre is the apex. 

 There is a marked difference (indicated in the 

 figures) between that part of the surface which 

 is exposed, and that which is covered by the 

 other scales ; the concentric marks in the former 



