130 THE ZOOLOGIST. 



movements are so intermittent and impeded, and, as already 

 stated, restricted to a few hours in the night. From the upper 

 reaches of the Ouse in Bedfordshire Eels would have a journey 

 of some one hundred miles before reaching the Wash, and under 

 all circumstances it seems probable that such a journey would 

 take at least a month or more to complete. 



The number of years that Eels remain in these waters before 

 returning to the sea seem to vary considerably, and it is difficult 

 to satisfactorily account for this retarded migration. 



The largest Eels taken are usually females, the females 

 growing more rapidly and attaining a larger size than males. 



There is a considerable variation in the colour of the 

 migratory silver-bellied Eels ; they range from pale green to 

 black and light yellow to dark brown. By many Eel-trappers 

 these are considered two separate species, the former being 

 termed " Black Eel," and these are said to be generally of large 

 size. Then, again, the undeveloped and at present non-migra- 

 tory yellow Eel is termed the "Yellow-bellied Eel " and " Mud 

 Eel " ; these are considered a smaller species. Those Eels that 

 have developed the enlarged mouth that is attained previous to 

 their final transformation are spoken of as " Frog-faced Eels " 

 and "Bull-headed Eels." 



There is a strong belief that Eels feed and enter into any 

 carcase lying in the water and will be seen to leave such bodies 

 when disturbed. Hence we occasionally hear this ignorant and 

 ghastly story applied to drowned persons. 



There is no doubt that the Eel from a commercial standpoint 

 is worthy of more consideration, and the present decreasing 

 supply obtained could be very much increased by reasonable 

 protection. There should be a close season for them at the 

 sluice traps during part of the migration period, and some 

 means devised of helping the young Eels to overcome more 

 easily these difficulties of access to the upper reaches of the 

 river. 



