DETAILS OF EXPERIMENT. 231 



transmitted throngli their expanded fronds. Many 

 of my friends, both scientific and unscientific, who 

 have seen my vases of growing Algae at various times 

 during the present year, both at Torquay and at this 

 place, have expressed strong admiration of the beau- 

 tiful and novel exhibition. 



I have not as yet been able to presence the water 

 to an indefinite period. Sometimes the experiment 

 has quite failed, the plants decaying and the animals 

 dying almost immediately ; but more commonly, the 

 whole have been preserved in health for several weeks. 

 The following, are the particulars of the most success- 

 ful of my eflforts. 



On the 3rd of May I put into a deep cylindrical 

 glass jar (a confectioner's show-glass) 10 inches deep 

 by 5|- inches wide, about three pints of sea-water, and 

 some marine plants and animals. 



On the 28th of June following, I examined the 

 contents of the jar as carefully as was practicable 

 without emptying it, or needlessly disturbing them. 

 It had remained uncovered on the tables in my study, 

 or sometimes in the window, ever since, a little w^ater 

 only having once been added merely to supply the 

 loss by evaporation. The water was perfectly clear 

 and pure. A slight floccose yellow deposition had 

 accumulated on the sides of the jar, but there was 

 verv little sediment on the bottom. I had taken no 

 note of the plants or animals when I had put them 

 in ; but as none of them had died, and none had been 

 either abstracted or added, the following enumeration 

 gives the original as well as then present contents. 



There were at this time in the jar the following 



