224 Memorial of George Brozvn Goode. 



H. — TYPES AND UNIQUES. 



1 . These should always be marked in some conspicuous and unmistak- 

 able manner, and if not placed in special cases so labeled that their 

 value may be understood by all. ' 



The safety of types should be provided for by special rules, and it is 

 doubtful whether they should ever be allowed to leave the building in 

 which they are deposited. 



2. In zoology, botany, or mineralogy a type is a specimen which has 

 been described in giving a new specific name. Besides types of new 

 species there are equally valuable specimens which have served as the 

 foundation of critical revisions or monographs of groups, which are 

 equally deserving of special protection. Specimens which have been 

 figured in standard works are subject to similar treatment. 



I. — DUPEICATES. 



1. A duplicate, from the museum standpoint, is simply a superfluous 

 specimen. A collection may possess scores of specimens at first view 

 seemingly precisely identical, and yet not be able to spare one of them. 

 Specimens can never be separated as duplicates until after the collection 

 to which they belong has been exhaustively studied and the results of 

 the study published. Even then there is danger in parting with them. 



Comment. —The practice in the United States National Museum is to reserve from 

 the material upon which a given memoir has been based enough to render it pos- 

 sible to rewrite the memoir from the beginning if every copy should be destroyed. 



2. In great museums of research it is necessary and practicable to pre- 

 serve extensive series of specimens, representing every possible variation 

 and a great number of localities. In smaller museums this can not be 

 done, except, it may be, in special fields, and the lesser museums can 

 usually throw a much larger proportion of specimens into the duplicate 

 series. 



3. The use of duplicates is for exchange and distribution. Their 

 value when thus dispersed depends upon the most accurate identification 

 and labeling, based upon comparisons with the reserve collection from 

 which they are taken. 



VII.— THE ART OF INSTALLATION. 

 A. — INSTALLATION METHODS. 



I. The arrangement and mounting of collections for exhibition, com- 

 monly known as their "installation," is an art worthy of serious atten- 

 tion on the part of every museum officer. This art is allied to certain 

 branches of architecture, especially that of interior decoration, but the 



' In addition to the usual label a wafer or painted spot of bright color — red or 

 green— greatly aids in making a type conspicuous. 



