REPORT OF NATIONAL. MUSEUM, 1924 5 



cal explorations in North America, Central America, South America, 

 Asia, and the islands of the sea have added much desired material 

 representing the fauna and flora of those regions, while productive 

 geological field work was carried on within the borders of our own 

 continent. 



The biological accessions greatly surpass those of the years imme- 

 diately preceding, both in numbers and in scientific importance. The 

 outstanding biological acquisition was the donation by Dr. J. M. 

 Aldrich, associate curator of insects, of his private collection of 

 nearly 45,000 specimens of dipterous flies, representing 4,145 named 

 species and many unnamed, with type material in 534 species. All 

 the insect types in the custody of the Pennsylvania Department of 

 Agriculture were given to the National Museum, and it is hoped 

 other States will likewise more and more assist in the building up of 

 the National Collections. Similar cooperation from a number of 

 State institutions and scientific establishments has hitherto advanced 

 the geological collections, but the action of Pennsylvania constitutes a 

 precedent in the biological field. Types deposited in the National 

 Museum are more accessible to specialists than when housed in State 

 and private institutions, and are much safer, as there is less likeli- 

 hood of change of policy. 



Activities in China resulted in comprehensive biological collec- 

 tions received through the liberality of Dr. W. L. Abbott and Col. 

 R. S. Clark, comprising mammals, birds, reptiles, etc., collected by 

 Charles M. Hoy and Arthur de C. Sowerby, respectively; through 

 the generosity of Rev. D. C. Graham, whose collections from Szech- 

 wan included many topotypes ; and through the gift of the National 

 Geographic Society from expeditions under F. R. Wulsin and under 

 Dr. J. F. Rock. Mr. Wulsin during 1923 reached the famous 

 Tibetan Lake Kokoran, but the collections from that locality have 

 not yet arrived at the Museum. An interesting biological collection 

 from Siam, made and contributed by Dr. Hugh M. Smith, is par- 

 ticularly important as linking up collections already in the Museum 

 from the Malay Archipelago and Peninsula with those of the coun- 

 tries farther north. 



Dr. W. L. Abbott during his expedition to the island of Santo 

 Domingo procured for the Museum a series of skins, skeletons, and 

 embryos representing a genus of rodents which had not been found 

 alive for nearly 100 years, also large numbers of plants, reptiles, 

 and amphibians. Dr. C. D. Walcott's Canadian expedition, Dr. 

 Casey A. Wood's visit to the Fiji Islands, Dr. T. D. A. Cockerell's 

 expedition to eastern Siberia, Dr. Paul Bartsch's trip to the Ba- 

 hames, and Gerrit S. Miller's visit to the Lesser Antilles also added 

 materially to the collections. The National Herbarium was greatly 



