FRESH-WATER JELLY-FISHES 



61 



were pinched off as tiny spheres about one - sixteenth 

 of an inch in diameter. No females of this jelly-fish were 

 ever discovered. The polyps lived on from year to year, 

 and budded off each season a swarm of pretty but futile 

 male jelly-fish. They ripened and died on attaining a dia- 

 meter somewhat less than that of a shilling. There were 

 many most interesting points made out as to their structure, 

 mode of feeding, and growth. You could keep them in a 

 tall glass jar supported over a small gas-jet (they lived 

 best at a temperature of 80 Fahr.), 

 and they would swim up by a series 

 of strokes to the top of the water, and 

 then drop like little parachutes through 

 the eighteen inches of depth to the 

 bottom taking in water-fleas and such 

 food on the way and immediately 

 would start upwards again. I used to FIG. 4. Four of the 

 take them alive in my pocket corked 

 up in a test-tube to show to friends. 



After they had disappeared from 

 the tank in Regent's Park (owing to 

 some unhappy cleaning of the tank) 

 they suddenly, in 1903, appeared it 

 seems incredible at Sheffield ! Then 

 they briefly showed up in 1905 at 

 Munich, and at Lyons had been captured in 1901 

 always in a tepid water-lily tank ! We never could 

 make out where they came from originally. Of course, 

 the polyp must have been brought into the tank with 

 some bundle of water plants from a tropical lake or 

 river, but we never had any indication as to when or 

 which. 



Since the days of the fresh-water jelly-fish of Regent's 

 Park, which was called (a name, but why should it not 

 have a name?) Limnocodium Sowerbii a jelly-fish of 



minute club-shaped 

 polyps adhering to 

 a root-fibre of a 

 water-plant. The 

 rounded end be- 

 comes nipped off 

 and swims away, 

 free, as a young 

 'elly-fish. 



