American Association of Museums 45 



The floor space included in the two wings is 6072 square feet, all of 

 which is devoted to display cases, with the exception of two portions, 

 each 16 x 15 feet, at the eastern end of the east wing, partitioned off 

 as rooms for the sorting and preparing of specimens. 



The floor arrangement of the cases is based upon stratigraphic 

 sequence. Table and wall cases Nos. 1-4 contain plants of Eozoic 

 and Paleozoic time. Table cases 5-9, Mesozoic. Table cases 10-12 

 and wall case 5, Neozoic. This sequence of the cases, while it is 

 primarily a geologic and phylogenetic one, illustrating the general 

 evolution of the vegetable kingdom from its beginning, as represented 

 by the remains found in the Eozoic crystalline rocks, to recent times 

 as represented by the contents of peat bog and other surficial de- 

 posits, is incidentally also a taxonomic one when broadly viewed, 

 inasmuch as the plants lowest in the scale of life predominate in the 

 older geologic periods and the higher types in the more recent ones. 

 In other words, the relative abundance, from the older formations 

 upward, of algae, pteridophytes, gymnosperms and angiosperms, 

 represented in the arrangement of the cases according to stratigraphic 

 sequence, represents also the taxonomic arrangement of the system- 

 atic botanical collections on the museum floors above. This scheme 

 of installation and sequence therefore brings the museum collections, 

 as a whole, into one harmonious expression of the principle of evolu- 

 tion in connection with the vegetable kingdom. 



Each collection from any limited locality, or made by any expe- 

 dition from a more extended area, is kept intact in the drawers of the 

 case where it belongs stratigraphically, as nearly as possible; although 

 occasionally the specimens may represent more than one geological 

 horizon. Whenever possible, also, a copy of the report or other 

 publication in which a collection is described or discussed is deposit- 

 ed with it, in order to facilitate reference to descriptions and illus- 

 trations. The only exceptions to maintaining the integrity of the 

 collections are that individual specimens may be withdrawn and 

 utilized for display purposes. 



