1901,] NATUKAL SCIENCES OF PHILADELPHIA. 745 



provided. The work of expansion is still in progress, and to 

 understand properly the advance that has been made it is necessary 

 to revert again to the removal of the Academy to its present quar- 

 ters in 1876. 



At that time only a ])art of the building as originally planned 

 had been completed, and the collections and library of the Academy 

 even then practically filled all the available space. The constant 

 inci'ease during the subsequent ten years caused such overcrowding 

 that the systematic arrangement of the museum became an impos- 

 sibility, and much valuable material was practically inaccessible. 



In 1889 and 1891 two appropriations of 650,000 each were 

 secured from the State Legislature. These sums, together with 

 private subscriptions, made possible the much-needed additions to 

 the premises. The Lecture Hall was completed the following year, 

 and formally opened on February 22, 1892. Lectures previously 

 given in the Library have since then been delivered in the new 

 Hall, which has been furnished with a lantern and screen and 

 seating accommodations for 350 persons. 



The new wing of the museum was not completed until some 

 years later and was finally opened on October 20, 1896. 



Owing to the lack of funds only two floors could then be 

 opened, and only a part of one of them was furnished with new 

 cases. Since then, however, new cases of plate glass with oak or 

 mahogany woodwork have almost entirely replaced the old ones on 

 these floors, as well as in portions of the old building, and the 

 furnishing of the third floor of the new Museum is so far advanced 

 that it will be opened during the coming year. 



In the character and care of the various collections the greatest 

 changes have taken place, mainly since the recent increase in our 

 endowment, though in several departments the plans were laid 

 and work begun several years ago. The old idea of exhibiting 

 every specimen has been dispensed with, and the need of study 

 collections of large series of specimens has been recognized. 



Large numbers of birds and mammals, especially types and 

 unique specimens, have been unmounted and stored in moth-proof 

 cabinets, free from light and dust, and their preservation insured. 

 These have been arranged in the study rooms, whei'e they can be 

 easily examined, while still larger numbers of similar study speci- 

 mens have been added by purchase and gift. A corresponding 



