130 THE STORY OF FISH LIFE. 



hair, which dropped into the water from the tails 

 of horses when they came to drink. After long 

 soaking they became endowed with life, and 

 turned into worms. These worms, almost hair- 

 like in thinness, were known as "hair-eels," and 

 they in course of time completed the wondrous 

 transformation by developing into true eels ! 



There never was a mystery but some one was 

 ready with an explanation. The above effort to 

 throw light in a dark place was regarded as 

 quite satisfactory by people of not so very long 

 ago. In that explanation we see now a sug- 

 gestion of that love of the fantastic, and the 

 wonderful, characteristic of the older generations. 

 A readiness to accept any hypothesis that pre- 

 sented itself without much question or demand 

 for credentials. But, as in so many other 

 instances, there is an element of truth per- 

 meating this untruth. This truth is represented 

 in so much as concerns the hair-eel. The 

 "hair-eel" belongs to a group of commonly 

 parasitic nematoid worms, the early stages 

 of existence of which are passed within the 

 bodies of aquatic insects, from which they 

 ultimately emerge to pass the adult condition as 

 free-swimming organisms. In this adult con- 

 dition the males at least bear a very remark- 

 able resemblance to horse-hair, being very 

 slender, hard, and shining black in colour. 

 Now, in the days when men believed that life 

 could be engendered from non-living matter, 

 given favourable conditions, there seemed no 

 reason to doubt but that horse-hair might 

 become, by sufficiently prolonged soaking, 



