Natural History of Nova Scotia. 655 



to derive their nourishment from the air alone; for the largest 

 species, the rock tripe, which our Indians use instead of barley 

 for their soups, grows most frequently upon the perpendicular 

 faces of ledges of rock. These vegetables, besides furnishing 

 food for the caribou, or reindeer, and protecting trees and 

 rocks from the effects of the weather, serve to introduce soil 

 upon hills of naked rock. It is first overspread with the 

 crustaceous species ; these are followed by the leafy kinds : 

 when they decay with age and crumble to pieces, their bulk 

 is but little diminished. As soon as an inch of turf is formed, 

 the caribou moss appears. A small portion of the rock is 

 changed to sand by the action of the turf. The Acadian 

 heath [Ceratlola ericbides L.~] and the Potentilla tridentata 

 finally spring up, followed, as the turf increases, by black 

 whortle, candleberry myrtle, and other shrubs. The small 

 long-limbed Hudson's Bay pine [Pinus Bankszawa Lamb.] is 

 usually the first tree that grows on these shallow soils, which 

 finally, if not prevented by fires, become capable of producing 

 timber of a useful size. 



The Fungi, those substances which we are accustomed to 

 call mushrooms and touchwoods, are a family of vegetables 

 which have a very different office : it is their business to 

 assist in changing dead vegetable matter to mould or turf. 

 Every dead vegetable ; the trees overthrown by the wind ; 

 the leaves which fall annually; the low branches and under- 

 wood which die of suffocation, are immediately attacked by 

 the Fungi, and soon reduced to an elementary state, in which 

 they may serve again to become vegetables. Under their 

 action the greater part of the vegetable disappears ; the fungus 

 occupies a considerable portion of the space which was once 

 filled by the wood, not unfrequently the one half; and it is 

 manifest, from the lightness of the remainder, that the greater 

 part must have taken an aerial form. This decomposition is 

 soon performed under the shade of w r oods, but much more 

 slowly in open situations. A considerable part of the wood 

 killed by fires continues sound till it falls, and is shaded by 

 the plants that spring up near it ; that is to say, dead vege- 

 tables are very quickly changed to aerial fluids only in those 

 situations where there is a covering of foliage above them, 

 which prevents the dissipation of their elements by absorbing 

 them from the air. It seems probable, that the Fungi, the 

 principal agents in decomposing dead vegetables, are, like the 

 corals, formed by animalcula. [This view may not obtain 

 any credit for the author of it, but is given here, that the dis- 

 credit, as well as credit, due to him may be awarded to him.] 

 The work they perform (an immense quantity) is analogous 



