REPORT OF THE SECRETARY. 9 



of water have been made, and the material, which has arrived here 

 from time to time, is exceedingly rich in marine invertebrates, par- 

 ticularly mollusks. 



This year's eflorts have resulted in the discovery of grounds with a 

 more prolific, varied, and interesting fauna than previously known 

 in this region. 



BOTANICAL EXPLORATIONS IN SOUTH AMERICA. 



Through cooperation with the Carnegie Institution of Washington 

 the Museum was enabled to benefit by an expedition carried on by 

 Dr. J. N. Rose during the summer and fall of 1914 along the west 

 coast of South America in furtherance of his work on the Cactacese. 

 About 3,000 specimens of cacti and other plants collected by him 

 have been permanently deposited in the National Herbarium. 



Dr. Rose explored a section through central Peru from Callao to Oroya, from 

 sea level to the top of the Andes, at an altitude of 15,G65 feet. Cacti were found 

 in the greatest abundance at an altitude of 5,000 to 7,500 feet ; but the various 

 species range from a few feet above sea level to as high as 12,000 to 14,000 feet. 



A second section was made across southern Peru, from Mollendo to Lake 

 Titicaca via Arequipa. The highest point reached was 14,665 feet. Here also 

 the cacti are found from near sea level nearly to the top of the Andes ; but the 

 most remarkable display is on the hills surrounding Arequipa, at an altitude of 

 from 7,000 to 8,500 feet. While the cacti are abundant in both these regions, 

 they are, with only a few possible exceptions, quite distinct. Side trips were 

 made from Arequipa to Juliaca and Cuzco, in Peru, and to La Paz, Oruro, and 

 Comanche, in Bolivia. 



On the pampa below Arequipa are found the famous crescent-shaped sand 

 dunes. Each dune or pile of sand is distinct in itself, often separated some dis- 

 tance froiu any other dune, and occurring, too, on rocky ground devoid of other 

 sand. The dunes are found on the high mesa some 5,250 feet above the sea. 

 They form definite regular piles of sand, each presenting a front 10 to 100 feet 

 wide and 5 to 20 feet high, nearly perpendicular, crescent shaped, ami from the 

 crescent-shaped ridge tapering back to the surface in the direction from which 

 the wind blows. These piles of shifting sand go forward about 40 feet a year. 



In Chile two sections were made into the interior — one from Antofagasta to 

 Calama, and one from Valparaiso to Santiago. The first is through the rainless 

 deserts of northern Chile, the whole region being practically devoid of all vege- 

 tation. The second is across central Chile, the hills an-d valleys of which are 

 veritable flower gardens, the hills often being a mass of yellow. Various trips 

 were made in the central valley of Chile and one journey along the Longitudinal 

 Railway of Chile extended from Caldera to Santiago. Special trips were made 

 for certain rare plants like Cereus castaneus, first collected in 1862 and not since 

 observed until found by Dr. Rose ; and Cactus liorridus and Cactus Berteri, de- 

 scribed in 1833, but long since discarded by cactus students. In the central 

 valley of Chile is seen that beautiful palm, the only one native of Chile, JuMea 

 spectabiUs PI. B. K., which often forms forests of considerable extent. From 

 this palm is made the " Miel de Palma " so much used as a sirup on ships and 

 at hotels. 



Botanical explorations by Dr. Eose on the east coast of South 

 America were in progress at the close of the fiscal year. 



