32 



like roots, which had shot out into the air, and were not less 

 than six inches from the ground, which, however, they made 

 no effort to reach. They did not increase in length, shewing 

 that their function was to hold the plant in its place, and 

 that this function being already performed by the dead stem 

 there was no need for them to grow longer. Why the fleshy 

 nature of the leaves peculiarly fits the plant for a barren soil 

 and a salt air is not so easily determined ; partly, probably, 

 by the abundant supply of moisture thus contained — as in the 

 stomach of the camel — within the plant itself, rendering it in- 

 dependent of the moisture of the soil, and partly by increasing 

 the power of secreting from the air the carbonic acid, to 

 which, decomposed as it is in plants by the agency of light 

 alone, the woody constituents of the plant have to look for 

 their sustenance. 



The presence of iodine and of the salts of soda in sea-side 

 plants is accounted for by their neighbourhood to the sea, 

 the great source of both, and the absence of these in such as 

 grow at the tops of mountains is similarly explained. But 

 apparently these Halophytes cannot do without salt, so not 

 being able to get soda from the sea, they take potash from 

 the land, and thrive upon that. The procumbent growth of 

 the plants I have given reasons for ; but I am not chemist 

 enough to offer a reason for the prevalent glaucous colour, 

 though I may have my conjectures. 



I must now leave the subject for yourselves to follow out. 

 I hope any of you who may have the chance will especially 

 look out for these sea-side plants in the course of your Sum- 

 mer rambles. I should like to have said a few words upon 

 various intermediate forms, such as one of the two forms of 

 the common Bladder Campion, both of which may be found 

 between the *' Valiant Sailor" and the Lady-Wood, and also 

 upon sea-side ferns. But in mercy to you, as well as to 

 myself, I must stop. 



Tea was provided in appropriate style at 4.30 o'clock, and 

 by the time it was over the train had called again for the 

 members. 



