HYDRAS. 155 



CHAPTER VI. 



HYDKA8. 



WHEN Hercules was going about doing those wonder- 

 ful things of which we have all heard, it was suggested 

 that he should turn his attention in the direction of 

 Lake Lerna, near Argos, where a monster with a hun- 

 dred heads was making itself unpleasantly active. He 

 visited the place and interviewed the creature, but when 

 he had cut off one of the heads, he must have been sur- 

 prised to see two new ones sprout out of the bleeding 

 surface. It was discouraging, but the hero began to 

 have the best of the contest when he began to burn the 

 fresh cuts with a hot iron. The monster was the Hy- 

 dra of mythology. Science has preserved its memory 

 by giving the name to a common and curious creature 

 inhabiting all our ponds and ditches. The fresh-water 

 Hydra (there are no salt-water Hydras) has a soft and 

 elastic body attached by the tip of one end to an aquat- 

 ic plant or other submerged object, and eight or ten 

 long fine arms arranged around a mouth at the op- 

 posite end. 



There are two species, the green (II. mridis) and the 



brown (H.fusca), both being very common. The whole 



animal is elastic, and when extended may be an inch 



long and easily visible to the naked eye ; when con- 



8 



