22 BOTANY OF THE ROUTE. 



ten to forty feet liigb, and generally parallel to the mountains. At sliort intervals occur lakes, 

 small but beautifully clear, though usually without visible outlet, the gravelly soil rapidly 

 absorbing the water during the dry season. Few, however, dry up completely, and they 

 become neither muddy nor stagnant, thus indicating, perhaps, a subterranean flow. Around 

 these are beautiful groves of poplar, aspen, ash, maple, and a few pines and oaks. Scattered 

 over the surface are rounded hills, looking like islands in the level plain, and covered with 

 groves of the usual fir, which also sometimes grows on the slopes of the terraces. The whole 

 plain looks like a magnificent park ornamented by the highest skill of the landscape gardener, 

 while to the southeast, and in full view from all parts of it, stands the majestic Mount Rainier, 

 forty miles distant, though in appearance not more than five. 



On the much discussed subject of the moutds so abundant on the praries about Puget 

 Sound, I must make a few remarks, since Mr. Gibbs has suggested that they might have been 

 produced by the immense growth of the "giant root," {McfjarJiiza Oregana,) forming a nucleus 

 around which the soil has been gradually washed away. — (Vol. I, p. 469.) I have noticed this 

 plant quiteas often on level ground and in hollows as on these mounds, and have found deep 

 cavities where its roots have decayed. I cannot, therefore, consider it a cause any more than 

 roots and stumps of other kinds, which never produce mounds so symmetrical and uniform as 

 these are found. I would suggest that they may have been produced by eddies and whirlpools, 

 probably at a time when this sound formed the estuary of a great river like the Columbia, or 

 perhaps these prairies were branches of the great system of northwest sounds, which extends 

 from the Columbia river to Sitka, or further. I have seen such whirlpools in the narrow inlets 

 of the sound, during the violent ebb of the tide, that seemed to me quite capable of thus 

 raising mounds of gravel, just as is done by the eddies of the Avind with the light sand along 

 the sea shore and on the plains. Any vegetable origin must be quite inadequate to produce 

 such mounds as I have seen along Black river, which I believe were never seen by Mr. Gibbs. 

 There they stand so close together that it is impossible to walk between them without stepping 

 on the adjoining slopes, and, Avhilo standing at their bases, I could not see over them. Such 

 covered the surface for miles near the western border of the prairies, there being rone in the 

 adjoining forest. Their form, as is there most distinctly marked, is very perfectly circular ; 

 height from a scarcely perceptible swell to eight feet, and diameter at least six or eight feet. 

 Their bases do not coalesce, though close together when they are well marked. The low ones 

 seem to have been partially covered, so as to conceal their bases, and form level intervals 

 between the summits that still protrude. 



Note. — Mr. Gibbs, in his Geological Report, dated two months later tlianthc above reference, 

 (Vol. I, p. 486,) says that their origin "is clearly due to water.'' 



In a journey up the Chehalis and down the sounds to the Straits of Fuca, in March, 1855, I 

 found vegetation as far advanced as is usual in May at New York. Strawberries, <fec., were 

 beginning to flower, and many summer birds had arrived, including the delicate humming bird, 

 swallows, and warblers. Indeed, the mildness of the winters makes the prairies more green 

 and beautiful at that season than in summer, and up to the end of December, 1853, I found 

 several flo-w ers still blooming about Vancouver. 



Many of the richest prairies are much injured by a dense growth of fern or brake, which 

 grows on them eight feet high, and as it also occurs about two feet high on the poorer soils, 

 becomes a sure indication of richness. It is said that by cutting ofi" for a few times at a height 

 of several inches the stems will "bleed" to death, the sap running so as to exhaust the roots. 



