16 United States Exploring Expedition. 



Including the mosses, lichens, and sea-weeds, the number will 

 exceed ten thousand. Besides dried specimens, two hundred 

 and four living plants were brought home, and are now in the 

 green-house in the yard of the Patent Office, along with many 

 others raised from seeds. The kinds of seeds obtained, amount 

 to eleven hundred and fifty six. Many of the expedition plants 

 are now growing in the various green-houses of the country, and 

 also in England and Europe. Specimens of different woods have 

 been preserved, the most interesting of which are those of large 

 arborescent species of Oxalis, Viola, Ripogonum, Piper, Geranium, 

 Argyroxiphium, Dracophyllum, Rubus, Bromelia, Lobelia and 

 Compositae of various kinds, besides sections of the Tree Ferns 

 and Palms of the tropics. There are colored drawings of one 

 hundred and eighty species of plants, beautifully executed. 



Besides the observations at which we have glanced, in the de- 

 partments of zoology and botany, particular attention was paid 

 to the geographical distribution of plants and animals, and many 

 important facts have been ascertained. The reports on this sub- 

 ject, with the accompanying illustrative maps, will be found to 

 be among the most interesting of the results of the expedition. 

 This subject bears upon the distribution of fossil animals, and 

 the early history of our globe, and is exciting much attention 

 among those interested in geological investigations. 



The regions examined by the expedition have been highly 

 interesting in a geological point of view. The islands of the 

 Pacific east of New Caledonia are either basaltic or coralline. 

 A large number of the latter (as already stated) have been ex- 

 amined, and much that is important has been brought to light. 

 The facts strongly confirm Darwin's theory with regard to the 

 formation of these islands, but lead to very different conclu- 

 sions respecting the areas of subsidence and elevation in the 

 Pacific. Numerous facts bearing upon this subject were col- 

 lected. The basaltic islands are of various ages, from the most 

 recent volcanic to a very remote period probably as far back 

 as the middle of the secondary era. The older islands are re- 

 markable for their singular topographical features. There is 

 scarcely any part of the world where such profound gorges, 

 and sharp and lofty peaks and ridges, are thrown together in 



