GEOLOGICAL COLLECTIONS. 103 



and only used for consultation and reference by duly accredited 

 students.* 



In some parts of the Museum the reserve collections are 

 contained in drawers beneath the cases in which the corre- 

 sponding exhibited portion is placed. This applies princi- 

 pally to the fossil specimens, the shells, and the minerals. 

 The reserve birds and insects have special rooms devoted to 

 them, and the extensive series of reptiles, fishes, and other 

 animals preserved in spirit is kept, for the purposes of 

 safety, in a separate building behind the Museum. In the 

 Botanical Department the reserve collections are kept as 

 usual in the well-known form of an Herbarium, or Hortus 

 siccus. 



The great bulk of the specimens being arranged in these Suppiemen- 

 three series, supplementary collections for facilitating the study *?'^ Colieo- 

 of the distribution of animals and plants, and perhaps also of 

 minerals, in space and in time would be advantageous. The first, 

 constituting a geographical series, might show by Ulustrative 

 examples the leading characteristics of the fauna and flora 

 of each great region of the earth's surface; the second, or 

 geological series, would give examples of the fossil remains 

 found most abundantly in each formation, arranged so far as 

 may be in chronological order. 



The only attempt hitherto made at exhibiting a geographical Geographieal. 

 series in the Museum is the collection of terrestrial and fresh- 

 water vertebrated animals of the British Isles, arranged in the 

 pavilion at the west end of the bird gallery. It would be 

 difficult in the present building to find room for other geo- 

 graphical collections, however interesting and instructive. 

 With regard to geological collections, although the specimens Geological, 

 in the department so called are mainly arranged not geologi- 

 cally, or according to stratigraphical position, but according 

 to their natural affinities, yet, in many cases, it has been 

 found convenient to adopt a mixed arrangement, the specimens 

 within each large natural group being classified according 

 to the sequence in age of the strata in which they were 

 found. Such an arrangement, however, is only applicable to 

 the fossils of a particular region, owing to the difficulties in 

 * For conditioBS as to admission and regulation, see p. 123. 



