YOUNGER YEARS OF A PLANT. 177 



to reflect what little heat is found in such high latitudes. 

 The bark is, moreover, the last part of a plant that de- 

 cays, and in some trees may be called almost indestruc- 

 tible. Thus Plutarch and Pliny both tell us, that when, 

 four hundred years after the death of the great lawgiver 

 Numa Pompilius, his grave was opened, the body of the 

 king was a handful of dust, but the delicate bark, on 

 which his laws had been written, was found uninjured by 

 his side. 



Not all stems, however, are of the same firm, upright 

 structure. Nature shows beauty not only in the forms 

 themselves, but even more in their endless variety. In 

 the cactus family stems are represented by what we com- 

 monly, though erroneously, call their leaves, viz., fleshy 

 expansions, tumid with watery juice, and clothed with a 

 leathery cuticle, instead of bark. Of all cactuses, but one 

 has real leaves: all others possess little more than mis- 

 erable substitutes in the form of tufts of hair, thorns and 

 spines. These only, as far as they go, are their true 

 leaves. The stems, it is well known, display in this same 

 family an unusual variety of odd, outlandish-looking shapes. 

 Now they rise, under the name of torch-thistle, in a single 

 branchless column to the height of forty feet ; and now 

 they spread their ghastly, fleshless arms in all directions, 

 like gigantic funereal candelabras. The melon-cactus imi- 

 tates, in shape and bristling spines, the hedgehog to per- 

 fection, whilst the so-called mammillaria are smooth or 

 ribbed globes of all sizes. Others, at last, grow lon- 

 gitudinally, like the long whip-like serpent-cactus, which 

 swings ominously from the trees on which it lives as a 

 8* 



