Prof. Asa Gray on Sequoia and its History. 53 



the President of this association to a biennial plant. He 

 flourishes for the year in which he comes into existence, and 

 performs his appropriate functions as presiding officer ; when 

 the second year comes round, he is expected to blossom out 

 in an address and disappear. Each president, as he retires, is 

 naturally expected to contribute something from his own in- 

 vestigations or his own line of study, usually to discuss 

 some particular scientific topic. 



Now, although I have cultivated the field of North-American 

 botany with some assiduity for more than forty years, have 

 reviewed our vegetable hosts, and assigned to no small number 

 of them their names and their place in the ranks, yet, so far as 

 our own wide country is concerned, I have been to a great 

 extent a closet botanist. Until this summer I had not seen 

 the Mississippi, nor set foot upon a prairie. 



To gratify a natural interest, and to gain some title for ad- 

 dressing a body of practical naturalists and explorers, I have 

 made a pilgrimage across the continent. I have sought and 

 viewed in their native haunts many a plant and flower which 

 for me had long bloomed unseen, or only in the hortus siccus. 

 I have been able to see for myself what species and what forms 

 constitute the main features of the vegetation of each succes- 

 sive region, and record (as the vegetation unerringly does) the 

 permanent characteristics of its climate. 



Passing on from the eastern district, marked by its equably 

 distributed rainfall, and therefore naturally forest-clad, 1 have 

 seen the trees diminish in number, give place to wide prairies, 

 restrict their growth to the borders of streams, and then dis- 

 appear from the boundless drier plains, have seen grassy 

 plains change into a brown and sere desert — desert in the 

 common sense, but hardly anywhere botanically so, — have seen 

 a fair growth of coniferous trees adorning the more favoured 

 slopes of a mountain-range high enough to compel summer 

 showers — have traversed that broad and bare elevated region 

 shut off on both sides by high mountains from the moisture 

 supplied by either ocean, and longitudinally intersected by 

 sierras which seemingly remain as naked as they Avere born — 

 and have reached at length the westward slopes of the high 

 mountain-barrier which, refreshed by the Pacific, bears the 

 noble forests of the Sierra Nevada and the coast-range, and 

 among them trees which arc the wonder of the Avorld. As I 

 stood in their shade in the groves of Marijwsa and Calaveras, 

 and again under the canopy of the commoner redwood, raised 

 on columns of such majestic height and am])legirtli, it occurred 

 to mc that I could not do better than to share with you, upon 

 this occasion, some of the thoughts which possessed my mind. 



