to forestry, agriculture, marine, and wildlife resources (in particular with the end of the bird plume trade resulting in losses in local income and revenue). Official publications of the time likewise reflect the era. Hardly a mention of Dutch New Guinea appears, for example, in Handbook of the Netherlands East Indies (1924, Buitenzorg). By the late 1930s two substantial works had appeared, both with some natural history and resources content, the latter also covering exploration. These were the Australian Official Handbook of the Territory of New Guinea (1937, Canberra; reissued 1943) and the more ambitious Dutch (but New Guinea–wide) compendium, W. C. Klein’s three-volume Nieuw-Guinée (1934–1938; see References section below).
During the quarter-century between the wars, developments lessened the need for large expeditions, while at the same time more individuals were working for greater or lesser periods in the field—a number of whom have left accounts of their adventures. Innovations such as radio and the airplane, as well as aerial photography (well covered, for example, by Klein, 1934–1938), were of particular importance. The number of administrative, mission, and other posts also increased. Although the majority of these posts continued to be on or near water, some church groups (notably the Sacred Heart Roman Catholic mission at Yule Island and the Lutherans at Simbang and Sattelberg) had by then developed extensive graded track systems to their interior mountain stations. There were also some—generally less elaborate—systems of government tracks, including the track across the Kokoda Gap. Motor roads, however, remained few, but from the late 1920s this lack was partly offset by airstrips and the rise of commercial aviation, notably in the Mandated Territory. By the 1930s air links with nearby parts of the Indies and with Australia had also been developed.
Collectors and specialists were still predominantly European, but now they came to be joined by others from elsewhere, particularly Japan, Australia, and, increasingly, the United States. There was moreover a greater amount of collaboration than in previous decades, although a partial vogue for expedition reports remained (Nova Guinea, Results of the Archbold Expeditions, etc.).
GENERAL UNDERTAKINGS
The first major expeditions of the era between the two World Wars were the two over 1920–1922 in Netherlands New Guinea aimed at reaching Mt Wilhelmina (now Mt Trikora)—the furthest point reached by the Herderschee expedition of 1912–1913—but across the central range from the north, as earlier attempted by Moszkowski. The last great exploring expeditions in the pre–World War I style, these "New Guinea Expeditions" were led in turn by Dutch Army captains A. J. A. van Overeem (1920–1921) and J. H. G. Kremer (1921–1922). The approach for both was up the winding Mamberamo River through the Van Rees Mts into the Lake Plain, with van Overeem going up the Idenburg, Rouffaer, and Doorman rivers, finally reaching the Swart Valley and the summit of Mt Doorman (the highest peak along the northern fall of the Nassau Range). Camps were set up at Prauwenbivak, Bivak Batu, Pionierbivak, Doormanpadbivak, Mamonbivak, and Kikkerbivak. After reorganization and resupplying, Kremer (with 800 men!) returned to the field and retraced much of the previous route to the Swart Valley; from there some of the party crossed into the western Baliem basin (missing, however, the Grand Valley) and finally reached Lake Habbema (first seen in 1909) and nearby Mt Wilhelmina (now Mt Trikora)—at the end of the longest largely pedestrian supply line ever organized in New Guinea.
But, as Souter wrote in 1963 (see Reference section, below), the van Overeem and Kremer expeditions were the last of their kind. Never again would such battalion-sized parties take to the field; future large expeditions would rely on radio (first tested by van Overeem), fixed-wing aircraft, and (after World War II) helicopters and motor vehicles. Indeed, the size of these expeditions—particularly in 1921–1922—were not commensurate with the scientific results. The onset of a severe economic recession in the Netherlands East Indies also frustrated any new official plans.
Collections in the first phase of these two major 1920–1922 expeditions were made by W. C. van Heurn (animals) and H. J. Lam (plants, Bogor, Leiden, Utrecht), the plants written up in Nova Guinea and elsewhere. In Fragmenta Papuana (English version, 1945) Lam also presented a narrative and set of observations from his work which remains an accessible account of the van Overeem undertaking. Circumstances in the second phase of these expeditions were less favorable to biological collecting; the only substantial contribution was the work of the ethnographer-anthropologist Paul Wirz, who in 1922 remained in the Swart Valley while the rest of the party pushed southwards. He also collected animals (Leiden, Amsterdam), obtained both from there and on Mt Doorman. A few plants (Leiden) were, however, obtained by Hubrecht who was with the main party and moreover a veteran of Herderschee’s successful ascent.
The van Overeem and Kremer expeditions were followed in western New Guinea by the "Netherlands-America Expedition" of 1926 under M. Stirling, with the former Dutch army officer C. C. F. M. le Roux as topographer-ethnographer and W. M. Docters van Leeuwen from Buitenzorg as botanist (collections, Bogor, Leiden). While more of an explorer (as well as an anthropologist), Stirling (with his pilot R. K. Peck) pioneered the use of aircraft in New Guinea as a transport aid. Their route to the Lake Plain was similar to that of van Overeem and Kremer, and some of their campsites—in fact dating back to the time of the Dutch Military Expeditions (Militaire-Exploratie) of 1907–1915—were reused (Le Roux making some side trips). It was along this stretch that their amphibious plane saw most use. The upper route followed the Rouffaer River along and then into the Nassau Range up to an altitude of 2,600 m (with Explorationbivak the most distant camp). Deterioration of the plane, however, forced its withdrawal and so brought a premature end to the expedition. Few direct results ever appeared; in particular, both in 1932 and again during World War II, key notes and lists relating to the botanical collections were lost. Only gradually have the collections themselves (often with little data) been worked up as particular families have been revised. The major contribution was thus le Roux’s three-volume monograph on Papuan mountain dwellers, De Bergpapoea’s van Nieuw Guinea en hun Woongebied (1938).
The last years of the Jazz Age boom saw three biological "cruises" arrive in New Guinea waters: two American, one Belgian. The first was the Whitney South Seas Expedition of 1928–1929, which collected birds in eastern Papua and in the Milne Bay Islands (AMNH); it also was active elsewhere in the Pacific. The second was the visit in 1929 of Crown Prince Leopold of Belgium (later Leopold III) and his wife Princess Astrid, together with their chief scientist Victor E. van Straelen. During a voyage that ranged widely through the Netherlands Indies, they visited several spots in western New Guinea, including the Raja Ampat Islands, Sorong, Manokwari, the Arfak Mountains and Anggi Lakes, Yapen Island, and, in the south, Triton Bay (the site of long-abandoned Merkusoord). Van Straelen’s collections of insects, other animals, plants, and fungi are in Belgium (in Brussels and Meise (BR), respectively), but among the plants and fungi are only algae, mosses, and lichens. A special series from the Natural History Museum in Brussels (of which van Straelen was, in time, director) along the lines of Nova Guinea, Résultats scientifiques du Voyage aux Indes Orientales Néerlandaises..., encompassed algae (1932) as well as the extensive zoological results. Van Straelen also wrote a more popular book, De Reis door den Indischen Archipel van Prins Leopold van België.
The last "cruise," also in the first half of 1929, was the Crane expedition on its yacht Illyria. Sponsored by the Field Museum in Chicago but also with some input from Bostonians, it was headed by Cornelius Crane and S. N. Shurcliff with as chief biologist a former Philippine National Museum ichthyologist, A. W. C. T. Herre. During this world cruise calls were made in the Solomon Islands, the Gazelle Peninsula of New Britain, Huon Gulf, the Sepik River, Manokwari, and Waigeo. The team collected marine specimens as well as many freshwater fish, other animals, and some 400 or so plants (FMNH; plants also at NY). As with the Belgian expedition, the results included a popular book, Jungle Islands (1930), as well as scientific reports by Herre and others (mainly in the Field Museum’s zoological series).
The 1930s would be marked by five large expeditions, three from the United States and two from the Netherlands (and East Indies). Those from the United States—the so-called Archbold Expeditions—were organized through the American Museum of Natural History, New York, and personally financed and led by a Standard Oil heir, Richard
