132 THE STORY OF FISH LIFE. 



these remarkable and puzzling fish were larval eels 

 not only of fresh water, but marine forms also. 

 These larvae, furthermore, brought to light some 

 very extraordinary facts, one of the most impor- 

 tant of which concerns the law of growth. Thus 

 they go on increasing in size and favour daily, up 

 to a certain point, when they actually begin to 

 grow backwards, that is to say, they decrease in 



si ze from day 



to da 7 u P * oa 

 certain point, 



then growth 

 recommences; 

 with this new 

 growth they 

 assume the 



FIG. 12. Fish Transformations. A. B. C. Three i 



stages in the life history of the Eel : showing Characteristic 



the gradual decreasein size as the fish grows rnnnrl PP! li 

 older. With the decrease in size the eel-like Uj cc 



shape is gradually acquired. At C. the mini- form, ascend 



mum decrease has been reached. The young t flin OITT 



fish has now reached the "Elver" stage and L(J tllt3 



ascends rivers to complete its growth into the face of the 

 adult eel. i 



sea, and in 



the case of the fresh- water species, make their 

 way with all speed up the rivers, in which 

 journey we shall follow them in the next 

 chapter (p. 144). The accompanying figures give 

 an indication of the delicacy and transparency 

 of these fish at this early stage, the internal 

 structures in the living larva being quite dis- 

 tinct (fig. 12). The curious changes in the rate 

 of growth and the small size of the head, very 

 striking features of the larvae at this stage, are 

 also well brought out in the figures. When a 

 Leptocephalas has completed the first stage of 



