114 



DESCRIPTION OF PLATE I. 



THE HYDR^E, OR FRESH-WATER POLYPES. 



( PAGE 12. ) 

 [The Figures are slightly enlarged, for the sake of distinctness.'} 



FIG. 1. Three Green Polypes, (Hydra viridis"), attached to the stem of an 

 aquatic plant, p. 13. 



a, The base or pedicle of the Hydra. 



b, The mouth and arms. 



FIG. 2. The Common Fresh-water Polype, (Hydra vulgaris), partly con- 

 tracted, and the stomach distended with food. 



FIG. 3. The Long-armed Polype, (Hydra fused}, with the arms extended 

 in search of food, p. 15. 



c, A small red worm seized by one of the tentacula, or arms. 



d, An aquatic insect, caught by another of the arms. 



FIG. 4. The Hydra vulgaris attached to a twig : two young ones are 



seen sprouting from the sides of the body, p. 14, 

 FIG. 5. The Hydra vulgaris in a contracted state. 

 FIG. 6. The Hydra fusca moving to and fro in the water in quest of 



prey, p. 15. 

 FIG. 7. The Hydra fusca, with a worm, which it has partly swallowed ; 



the extremities hanging out of the mouth, and secured by 



the tentacula of the Polype, p. 15. 



