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The Museum Gazette 



"flower " or "fruit." It, however, must not have all the credit 

 of the greenness which we see, for many tracts of bark are 

 simply green over without displaying any visible covering. 

 These are really painted by a minute and microscopic algal, the 

 relation of which to its companion growths is, as we shall see 

 presently, of the utmost interest. The patches which we have 

 irreverently likened to cheese plates are, as all know, lichens, 

 and so also are the shaggy tufts known as " old man's beard." 

 Thus we have mosses, algals, fungi and lichens of various 

 kinds all flourishing on our oak stem and combining to its 

 decoration. If it is asked how it comes that such various 

 guests have succeeded in implanting themselves on the bark of 

 the living tree, the reply must be that the trunk, as a tree, has 

 grown old, so old, indeed, that it has been unable to keep its 

 outermost layers of bark alive. It is their failing vitality 

 which has made them an easy prey to assailants which could 

 have availed nothing against them in their youth. You do 

 not see much moss or lichen on saplings. It might, perhaps, 

 be incorrect to say that any considerable thickness of the 

 outer bark is absolutely dead, but it is going that way. Death 

 may be said to be accomplished when the fluids cease to move, 

 and there is probably exceedingly little movement of the juices 

 in those islands of bark which we see surrounded by deep 

 cracks. We have, however, unconsciously left our attempt 

 at the description of outside beauty and have been drawn 

 into something like speculating on the nature of life. It is time 

 hat we gave place to the botanist with his lens. Indeed, we 

 have, perhaps, kept him waiting too long, and feeling assured 

 that — if we can only persuade him to forego his learned terms 

 — he will add much to the interest of the objects before us, 

 we will now beg him to tell us as much as he can about what 

 grows on the bole of an oak tree. 



Possibly several kinds of moss are present at the foot of 

 the tree, but the one which forms such a beautiful smooth 

 green on the bole is the cypress-leaved feather moss. 1 It 



1 Hypnum cupressiforme . 



