et a 
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1906] BERGEN—LITTORAL SPERMATOPHYTES 333 
ished effect of the salt in the presence of sand is in accordance with 
the conclusions of TRUE and OGLEVEES in regard to the lessened 
effect of toxic substances in aqueous solution in presence of inert and 
insoluble solids. 
None of the work done was shaped with special reference to deter- 
mining whether the injurious action of saline solutions on the plants 
examined was due to dehydrating or other physical effects, or whether 
it was purely toxic. A notable desiccation and shrinkage was often 
observed throughout the stem while the upper leaves and especially 
the terminal bud remained vigorous. This fact would tend to con- 
firm the hypothesis that the lethal action of dissolved salts is of a 
physical character. On the other hand, the fact that a pure sodium 
chlorid solution is usually more quickly fatal than sea water con- 
taining the same amount of sodium chlorid plus other salts tends to 
confirm the toxic hypothesis. Probably both factors may cooperate 
to produce death. Apparently the relative ease with which root 
hairs of the species studied can be plasmolyzed does not bear any 
definite relation to the susceptibility of the species to the action of 
sodium chlorid solutions. 
The principal conclusions reached may be summarized as follows: 
1. Association A consists of members very unequally resistant to 
the action of pure sodium chlorid solutions and of sea water. 
2. The tolerance of sodium chlorid on the part of some members 
of this association is considerably greater than that of ordinary non- 
littoral plants; in other words, they are facultative halophytes. 
3- Many of the species of this association are typical psammo- 
phytes, none are typical halophytes. 
4. Growth of a non-halophytic species for many generations in 
an atmosphere at times highly charged with saline spray does not 
bring about greater tolerance of saline solutions when absorbed by 
the roots. 
5- The Salsola seedlings studied showed a tolerance of sodium 
chlorid solutions up to almost 6 per cent. as good as that of any 
member of Association A for the 2.88 per cent. solution. 
NApLEs, ITALY. 
5 TrRuE R. H., and OctevEE, C. S., The effect of the presence of insoluble sub- 
‘stances on the toxic action of poisons. Bot. GAZETTE 39:1-21. 1905 
