These papers are concerned with five separate expeditions for collecting vertebrates in South America. The first three, in 1929-1932 were made to Peru, while the second two, 1933-1935 were to Bolivia. Melbourne A. Carriker was a Philadelphian interested in becoming a collector and through the sponsorship of the Academy and financial aid of Clement B. Newbold, he went to Peru where he collected birds and mammals. Later, on his Bolivian expeditions he was accompanied by his son M.R. Carriker and the expeditions were sponsored by the American Philosophical Society through grants to aid the collections. It developed that Carriker remained in South America and periodically returned to this area to keep up his contacts with museums and individuals wanting collections of specimens made in Peru and Bolivia.

The collection includes documents about the grants, financial statements, the itineraries, diaries and reports of the results of the expeditions. A good deal of correspondence is involved and we have 25 letters from Melbourne A. Carriker himself, dated 1933-35, and letters from various officials of the Academy of Natural Sciences, Abercrombie and Fitch for supplies, U. S. State Department and other state officials, publicity letters and news releases, as well as private letters within the family. The 1934-35 trip alone netted the Academy 2,249 bird skins and 18 mammals, embracing nearly 600 species, many of them new to science.