6o 



SCIENCE FROM AN EASY CHAIR 



in the Botanic Gardens, Regent's Park. It came up by 

 hundreds every year for some ten years after its first 

 appearance, dying down in six weeks or so each season. 



All the specimens were males, and the puzzle was to 

 find out how it reproduced itself. After a few seasons 



had passed I deter- 

 mined to solve this 

 problem. I made the 

 guess that perhaps the 

 jelly-fish were budded 

 off from a fixed weed- 

 like polyp growing in 

 the depths of the tank 

 as is the case with 

 many of the marine 

 jelly-fishes. I remem- 

 ber that one leading 

 member of the council, 

 which still presides 

 over the destinies ot 

 the Botanic Gardens, 

 confided to me in a 

 hushed whisper his 



FIG. 3 .-The fresh-water jelly-fish (Limnoco- belief that Providence 

 dturn] enlarged four times linear measure- , , . ... 

 ment, as it is seen dropping through the Created this new jelly- 

 water in a glass jar. PT, one of the four fish year by year in 

 principal tentacles. MR, the margin of the tank in honour 



o^vdum. ^ thC ddiCate mUSCUlai " fri " f the aU S USt P atr n - 



ness of the Botanic 



Society Her Royal Highness the Duchess of Teck. 

 I was obliged to make an end of this flattering theory 

 when I discovered, after long searching with my assist- 

 ant attached to the rootlets of floating water weeds 

 a minute three-branched polyp (Fig. 4), from which, as 

 we subsequently were able to observe, the jelly - fish 



