1910.] NATURAL s< tENCES OF PHILADELPHIA. 619 



of insects, plants, mollusks, birds, and mammals. The study col- 

 lections, it should be remembered, constitute the scientific basis of a 

 museum. Specimens in the exhibition cases have, for the mosl part, 

 a comparatively limited life and in course of time have to be replaced. 

 The study specimens, however, when properly housed and protected 

 from light, dust, and insect pests can he preserved indefinitely. 



It is therefore a matter for congratulation that the immense study 

 collections of the Academy containing the types and historic speci- 

 mens of a century of scientific research are being rapidly placed 

 beyond danger and their preservation assured. 



In no one year has such progress in housing these collections been 

 made as in that just closed. 



Early in the year the exhibit of the Pennsylvania Department of 

 Health, which was awarded the grand prize at the Panama-Pacific 

 Exposition, was received at the Academy and installed in the gallery 

 of the Mineralogical Hall, which was temporarily allotted to the 

 State for this purpose, the installation, lighting, and guarding of the 

 exhibit all being assumed by the State. 



The exhibit has proven very attractive and instructive and has 

 attracted large numbers of visitors. 



The attendance in the museum throughout the year has been 

 large and is constantly increasing, especially the numbers of classes 

 from public and private schools which come under the guidance of 

 their teachers. 



Local field work was carried on extensively by several members 

 of the staff, resulting in valuable additions to the collections of 

 fishes, crustaceans, reptiles, batrachians, etc. 



Mr. Clarence B. Moore has continued his exploration of the 

 Indian mounds of the Southern States and has provided an additional 

 case for the display of the valuable material secured during the year. 



Mr. J. A. G. Rehn was sent to Tucson, Arizona, where, through 

 the courtesy of the American Museum of Natural History, he joined 

 an entomological expedition to the adjoining desert regions. In 

 consideration of his services the Academy will receive a valuable 

 share of the material collected. 



Details of the work in the various departments and a list of the 

 accessions are appended. 



Mammals. 



An air-tight sheet-iron room was fitted up on the fourth floor, 

 close to the mammalian study collections, in which have been hung 

 41 



