Habits and Adaptations 263 



The little fish now swarm up the streams. The word 

 "swarm" is used advisedly. The numbers which survive to 

 reach fresh water can be only a small percentage of those 

 born in the Sargasso Sea, yet at times there are what appear 

 to be solid ropes of elvers ascending our rivers. One au- 

 thority speaks of getting fifteen hundred in a single scoop of 

 a small dip-net as something not at all unusual. Those which 

 survive this upstream passage — and the number eaten by fish 

 and other animals must be enormous — settle down to live 

 and grow in fresh water. They are voracious, but grow slowly. 

 Scales form, in the American species, at three to four years. 

 They are so deeply sunk in the skin that people often think 

 of eels as having no scales, but they are there, and they are 

 readable. Eels kept in captivity have been known to live for 

 fifty years, but they never breed in fresh water. 



Normally, the males grow to sixteen inches, the females 

 to three feet. Age at maturity varies from eight to fifteen 

 years; it is earlier for males than for females. But what- 

 ever it may be, there comes for each an autumn when some- 

 thing irresistibly impels it to go down to the sea. So strong 

 is the urge that if the water in which it dwells has been 

 isolated by drying streams, it will travel overland, choosing 

 damp nights for such excursions. Arrived in salt water, its 

 sex-organs begin to develop, it ceases feeding, and it starts 

 on its slow journey back to its birthplace. A French zoologist 

 has estimated that eels do not travel ordinarily faster than 

 one-half mile an hour. At this rate it would take the Ameri- 

 can eel from one to two months, the European eel about six 

 months, to make the journey. Great armies of eels, endless 

 processions of eels, from Maryland and Maine, from Eng- 

 land and France, from Cadiz and Trieste, solemnly wriggle 

 across the Atlantic at this funereal pace. They reach the 

 Sargasso Sea, they go down into its dark depths, and there, 

 a thousand feet below the surface, they spawn and die. 



