Marvels of Pond-Life. 33 



it gently on the walls of our cell. A few drops of 

 superfluous water escape, and we have the cell quite 

 full, and the cover held tight by force of the capillary 

 attraction between the water and the glass. 



The polyp deposited in one of these water cages is 

 then transferred to the stage of the microscope, and its 

 proceedings watched. At first it looks like a shapeless 

 mass of apple-green jelly. Soon, however, the tail end 

 of the creature is fixed to the glass, the body elongates, 

 and the tentacles (in this case eight) expand some- 

 thing after the manner of the leaves of a graceful 

 palm. 



By, accident two small Water Fleas were imprisoned 

 with the polyp, and one (a shrimp-like looking crea- 

 ture, carrying behind her a great bag of eggs) came 

 into contact with the tentacles, and seemed paralysed 

 for a time. The hydra made no attempt to convey the 

 captive to its mouth, but held it tight until another 

 Water Flea, a round merry little fellow (Chydorus 

 sphcericus), came to the rescue, and assisted Cantho- 

 camptus to escape by tugging at her tail. This friendly 

 action may not have been prompted by the intelligence 

 which seemed to suggest it, but those who have kept 

 tame soldier-crabs and prawns in an aquarium, will 

 not be indisposed to attribute to the crustaceans more 

 brains than they have usually credit for. It must, 

 however, be confessed that the subsequent conduct of 

 Mrs. Canthocamptus did not indicate the possession of 

 much prudence, for she learnt no lesson from experi- 

 ence, but repeatedly swam against her enemy's tenta- 

 cles, suffered many captures, and only escaped being 



3 



