iiistiuicc, a lirld 

 mouse witli its 

 enemies <>ii tlu' 

 one liatid and its 

 prey on the otlier 

 — is an e.\ain])l(' 

 ot" the stru.u'^ie 

 for existence. 



The Hall of 

 Mollusea. aims to do in detail for one dixision of 

 animals what the Darwin Hall outlines tor all. 

 Here an e.xtensive array of shells is placed, to- 

 gether with exhihits sliowiny' how im])ortant some 

 species are to man, such as the pearl oyster with 

 its pearl-fishiufi; industry, and the connnon oyster 

 and the elaiii with theii' cult ure and inihlstries. 



The Hall of Insect Biolojiy and Local Insects has a double function. 

 In it are deposited larj^er collections of insects ftmnd within fifty nn'les of 

 New ^ Ork so that a student can hriny his own cDllections for comparison 

 and identification. Here, as in the Darwin Hall, lar<ier ])rincij)les are 

 demonstrated, such as variation of the members of a sin<,de si)ecies, the 

 diiferences between insects of forests and of plains, the results of experi- 

 mental in\estigation of heredity, and the like. During the past summer 

 there have been in the hall special exhibits of the seventeen-year cicada and 

 of li\e bees at work in ;i hixc 



i 



V. THE MUSEUM LIBRARY 



Hji l\(i!j>li 11 '. Toircr 



TllK Librai'y of the American Mus<'um has been in existence since the 

 founding f)f the institution but not until \cry recent times has it 

 kept j)ace with other departments. Dm-ing the last decade how- 

 ever, enthusiasm has increased, some scientific societies ha\'e deposited their 

 books in the Museum's custody and altogether a serious attempt has been 

 made to make this library one of the most comprehensiNc and complete 

 of its kind in America. 



Library progress in general has been \'ery rapid in .\nierica in recent 

 years and one of the most important (le\-eloi)iiients in this progress has been 

 the rise and growth of the "special library," ])articularly the one whose 

 purpose it is to .serve the public in a free and um-estricted maimei-. 



A special library relating to natural history appeals not only to the 

 specialist whose needs demand accurate and detailed descriptions l)Ut al.so 



to a very large proportion of the pubhC where the desire is for more general 

 252 



