Explanation of the Cuticle of Leaves. 1 6 7 



double and unnatural flowers back to their ancient beautiful 

 simplicity. But this is not my business: to understand how far 

 a bulb will maintain itself without any extraneous aid ; whether 

 in this situation it is capable of giving life to others, as well as 

 to support itself, and how far this may be carried in bulbs ; and 

 to examine whether the seed can draw its soiu'ce from itself,, 

 or whether (like all other plants) it is created in the roots by 

 the joint juices of the sap of the earth wxA mother plant, is 

 what I am most anxious to discover ; also how long the nutri- 

 ment laid upon a bulb will last, and what it loses in weight. I 

 must here observe, that when it is not a bulb, t-he cuticles of the 

 grassy leaves differ extremely. 



Of all the cuticles of plants I have been studying, none have 

 puzzled me like the bog plants. They certainly differ much 

 both from rock and sand- plants; for they appear to receive al- 

 most all their nourishment from the root, and to depend on them 

 so much as to die if removed from that soil ; and yet they are 

 almo-it always to be discovered collecting moisture from the at- 

 mospliere, especially the scirp'i, and most particularly the 

 junci. All these certainly draw-in moisture from the sides of 

 their leaves ; as do all the azalias, which have the most curious 

 mechanism for that purpose. Now to require in so extreme a 

 degree botli the nourishment of root and leaves, is an uncom- 

 mon circumstance ; but I rather fancy it is not the moisture of 

 the hogs' i hat is required, but the peculiar earth with which it 

 is formed. It appears indeed far more easy for nature to sup- 

 ply her wants of moisture or dryness by the change of cuticle, 

 than to do without the sort of earth she is accustomed to ; and 

 there appear for all bog plants some ingredients in the earth 

 necessary to their well doing, and in which alone they can thrive. 

 To discover this is a matter I have much at heart, not merely to 

 make one set of plants do well, (though that would be a suffi- 

 cient incentive,) but as producing another fact of essential con- 

 sequence in our knowledge of the formation of plants. What this 

 portion of earth is, or what part of the bog matter it may be, I 

 am endeavouring to discover, having analysed the earth, and ex- 

 tracted by turns each separate ingredient." But as it is necessary 

 that the plant should grow in it, it requires many years to as- 

 certain the fact, arid complete the trial. Bog plants of the 

 Hzalia kind have Uiree cuticles above, and two" below, with a 

 thick pabulum not at all watery ; and this convinced me, they 

 could not draw much water from the atmospliere : for this appears 

 an invariable rule, that the more moisture the leaves take in, 

 the more loose and juicy is the pabulum. Most of the bog 

 plants have a very raised and glittering upper cuticle of the net 



L 4 kind. 



