*.l] GRAY AND HOOKER ON THE ROCKY MOUNTAIN FLORA. 63 



[n the district we inhabit Bach interference is so recent that we have little difitaulty 

 in conceiving the oonditions whioh hero prevailed, a few generations ago, when the 

 "forest primeval" — described in the Aral lines of a familiar poem -covered essentially 

 the whole count iy. from the Gulf of Saint Lawrenee and Canada to Florida and T< 

 Cram the Atlantic to beyond the Mississippi. This, our Atlantic forest, Is one of the 

 largest and almost the richest of the temperate forests of the world. That i-. it oonv 

 diversity oi' species than any other, except one. 

 In crossing the country from the Atlantic westward, we Leave this forest behind na 

 when we pass the western borders of those organised states which lie along the right 

 bank of the Mississippi. We exchange it for prairies ami open plains, wooded only 

 . the water-courses — plains whioh grow more and more hare and Less green as we 

 d west ward, with only some scattering Cottonwoods (i. e. Poplars) on the imme- 

 diate banks of the traversing rivers, which are themselves far between. 



Ill the Rocky Mountains we come again to forest, but only in narrow lines or patches; 

 and if you travel by the Pacific Railroad yon hardly come to any; the eastern and the 

 interior desert plains meet along the comparatively low Level of the divide which here 

 ipportunefor the railway; but both north and south of this line the mountains 

 themselves are fairly wooded. Beyond, through all the wide interior basin, and also 

 north and south of it, the numerous mountain chains seem to he as bare as the alka- 

 line plains they traverse, mostly north and south, and the plains beat nothing taller 

 than Sage-brush. But those who reach and climb these mountains find that their ra- 

 vines ami higher recesses nourish no small amount of timber, though the trees them- 

 selves are mostly small and always low. 



When tin' western rim of this great basin is reached there is an abrupt change of 

 This rim is formed of the Sierra Nevada. Even its eastern slopes are forest- 

 clad in great measure : while the -western hear in some respects the noblest arid most 

 remarkable forest of the world— remarkahle even for the numherof species of ever- 

 green tree> occupying a comparatively narrow area, hut especially for their wonder- 

 ful development in size and altitude. Whatever may he claimed for individual Eu- 

 calyptus tree-, in certain sheltered ravines of the southern part of Australia, it is 

 prObable that there is no forest to he compared for grandeur with that which stretches, 

 ially unbroken, though often narrowed and nowhere very wide, from the south- 

 ern part of the Sierra Nevada in latitude 36 to Puget Sound heyond latitude 49 . and 

 not a little farther. 



- ending into the long valley of California, the forest changes, dwindles, and 

 mainly disappears. In the Pacific coast ranges it resumes its sway, with altered feat- 

 some of them not Leas magnificent and of greater beauty. The Bedwoods of the 

 lor instance, are little less gigantic than the I'.ig-tives of the Sierra Nevada, and 

 far handsomer, and a thousand times more numerous. And several species which are 

 merely or mainly shrubs in the drier Sierra become lordly trees in the moister air of 

 tie- northerly coast ranges. Through most ot" California these two Pacific forest 

 separate; in the northern part of that state they join ami form one rich woodland 

 heir, skirting the Pacific, hacked by the Cascade Mountains, and extending through 

 British Columbia into OUT Alaskan Territory. 



re have two forest regions in North America— an Atlantic and a Pacific They 

 lies,- names, for t he\ are dependent upon t hi' oceans whioh t hej respectively 

 ; . Also we have an intermediate isolated region or isolated lines of forest, i! 

 on both sides by hare and arid plains — plains w Inch on t he eastern side may partly he 

 on the west.-l ; . 



This mid-region mountain forest is intersected by a n ■ • - 1 1 of arid and alka- 



line plateau, OT eastward Of grassy plain — a hundred miles wide from north to .south — 



through which passes the Cm on Pacific Railroad. This divides the £ 



mthern and a northern portion. Theaouthern Is complete! 

 ■ •I t hern, in a cooler and leas arid region, is larger, broach r, more diffused. Ti 



Bid, on and heyond thenorthern houndary oft I 



