1909] OLSSON-SEFFER— VEGETATION ON SEA SHORES 107 



sodium 



quantities, which the strand plants are able to tolerate without evident 

 injury. There appears to be a certain maximum amount of salt for 



ery 



cannot 



In some 



maximum 



Per cent. 



Per cent. 



Argentina anserina 1.9 Glaux maritima 2.7 



Aster Tripolhim 2.6 Juncus Gerardi ..2.2 



Atripex hastata maritima 3.1 Matricaria inodora maritima 2.3 



Cakile maritima 2.9 Plantago maritima 2.8 



Crambe maritima 2.5 Sonchus arvensis maritima 2.6 



EJymiis arenarius 2.6 Triglochin maritimum 2.1 



Efythraea vulgaris 1.9 



These experiments were conducted in the summer of 1894 with 

 plants from the Baltic coasts. Sand cultures saturated with normal 

 solution of sodium chlorid were used. In these cultures young seed- 

 lings as well as older plants were grown, and the results given above 

 refer to seedlings, about two weeks old at the time of transplanting. 

 They were grown in fresh water for five days, after which time the salt 

 solutions were gradually applied. It was found that plants which had 

 been growing on strands with low salinity were considerably more 



sensitive to an increase in 



brought in from the open shores with higher salt content in the water. 

 Strong, well-developed plants adapted themselves more readily than 

 weaker specimens to the gradual transfer to stronger salinity. It 

 would be of considerable interest to ascertain whether this specific 

 lmit of salt concentration could be raised much higher by growing 

 1 e Plants through a succession of seasons. The ability of the sea- 

 s ore plants to endure salt in the soil without injury and by adapting 

 ^emselves to these conditions has, no doubt, been the ultimate cause 

 ° their being in many cases confined to the strand, precluding com- 

 ^ 0n from f orms not possessing this power of resistance. 



« also know from experimental cultures that strand plants do 

 not need snrUi,™ „ui. • i • . « ^ u «.*; rtn 



The question 



common 



low u ""-" vi i "c common salt, even wnen pre^cm u* 4«""- 



j* than the maximum, exercises a poisonous influence or not. 



^HlMp ER _ u i ., , .. . .. .. .„ fU„ ™n- 



