THE BLOOD-WORM, 



299 



Blood-worms, natural size and magnified. 



is in reality not a worm at all, although resembling 

 worm in shape, and in its serpent-like movements. 

 This little creature was 

 for a time particularly 

 active ; and in a tumbler 

 of water taken from the 

 fountain might be seen 

 perhaps a dozen of them 

 twisting about in a very 

 singular manner. By- 

 and~by a change came 

 over them, and it turned out that the worm- 

 like creatures had become pupae of a blackish 

 colour, thus at once deciding their insect cha- 

 racter. They belong, in fact, to the insect 

 called the Chironomus plumosm. These black 

 pupae were scarcely less active than the red blood- 

 worms, or larvae of the same insect. They flapped 

 about their tails with great vehemence, and thus, 

 although their bodies naturally sink in the water, 

 they were able to swim from the bottom to the 

 surface, or from side to side. Observing that they 

 had finished their appointed period in the pupa 

 form, we became anxious to watch their change 

 into the perfect insect. Neglecting, however, to 



