Seasides and Strand Plants 
These are the joints of Salicornia herbacea, the salt- 
wort or marsh samphire, whose seeds germinate in salt- 
water (indeed they are more healthy in it than in 
fresh), and whilst still attached to the buoyant, cigar- 
shaped joint.* 
One of these seedling plants grounds in the salt mud 
on the top of the bank, and its roots at once grow 
vigorously, and very soon a small independent plant has 
established itself. Others no doubt accompany it, and 
the surface of the bank is soon overspread with this 
remarkable plant. It is extremely like a miniature 
cactus, and this succulence seems inexplicable, for why 
should it resemble a desert plant when it has water every- 
where, and indeed is daily submerged at high tide ? 
But the water is salt, and common salt is really a 
poison to vegetable protoplasm. The Salicornia, how- 
ever, has adapted itself to these conditions ; it can alter 
the density of its internal cell sap and so regulate the 
amount of water taken in.’ It has been found that the 
protoplasm of its root-hairs is healthy in so concentrated 
a solution as 5.8 per cent. of common salt. If, however, 
the root-hairs are left for two hours in 1 per cent. solu- 
tion, and then suddenly transferred to a 5.8 solution, 
the protoplasm shrinks together (or is plasmolysed).‘ 
This little experiment shows that it is able to regulate 
the density of its cell sap according to the saltness of 
the water, and so explains how it has been able to adapt 
itself to these dangerous conditions. 
One might compare its behaviour to that of people 
who accustom themselves to the eating of arsenic, and 
gradually become so trained to the poison that indeed 
they can hardly do without it. 
* Dr. Guppy ? found joints with fruits and apparently germinating seedlings 
off the coast of Peru. The seedlings in salt-water can live for some ten weeks 
but then die if they cannot attach themselves to salt mud. 
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