ARTICLES 79 



Delf * found that plants of Salicornia which were allowed 

 to wither for 4^ hours, during which period they lost 8 per 

 cent, of water, recovered 16 per cent, of their loss after 2 hours' 

 immersion in a 3 per cent, salt solution. 



Halket 3 found that in plants of Salicornia the percentage 

 of water in the succulent parts rose from 90-2 per cent, to 

 91-6 per cent, after immersion in a 3 per cent, solution of 

 sodium chloride. In subsequent experiments it was found 

 that the increase of water, calculated as a percentage of the 

 weight of the succulent parts, after prolonged immersion (17 

 to 20 hours) in a 3 per cent, solution of common salt, varied 

 from 5*05 per cent, to 26-7 per cent, in the case of S. ramo- 

 sissima collected at Erquy, whilst for a species of Salicornia 

 from Blakeney the variation was from -45 per cent, to 10*9 

 per cent. In the latter case the increase calculated as a 

 percentage of the weight of water in the succulent parts varied 

 from -49 per cent, to 1 1 -8 per cent. Also it was found that 

 if the plants were allowed to lose water before immersion in 

 the saline solution the amount taken up was greatly increased. 

 Thus, for Salicornia collected at Blakeney the plants gained in 

 weight from 20-8 per cent, to 53-7 per cent., again calculated 

 as a percentage of water in the succulent parts of the plant 

 at the time of immersion. 



Both observers agree that the gain after immersion is 

 less than the loss sustained during wilting, but in Halket 's 

 experiments the difference is very much smaller than in Delf's. 



These experiments show conclusively that the plants con- 

 sidered can make good some of their losses of water from sea- 

 water, although not to so great an extent as from fresh water. 

 It may be argued that in some of the above experiments the 

 gain may not amount to much since the time of immersion 

 was so much greater than the time the plants would be covered 

 by the tides. It has been found, however, that in cases of 

 prolonged immersion the greatest gain is made in the early 

 period of immersion, e.g. three plants of S. ramosissima after 

 5^ hours' immersion gained 20-69 per cent., 5-37 per cent., and 

 7*92 per cent, in weight respectively, whilst during the following 

 15! hours the gains were respectively 7-90 per cent., 2-78 

 per cent., and 3-65 per cent. And this obtains also when the 



1 Delf, Ann. Bot. 25, 485, 191 1. 

 s Halket, New Phyt. 10, 121, 1911. 



