221 
It should also be remarked that the number indicating the 
number of specimens collected (215) is more or less misleading 
for the reason that a large part of these consist of finely divided 
lignitic material, contained in vials or massed in bulk, each so- 
called specimen, therefore, including many individual specimens. 
ARRANGEMENT OF THE CoLLection. — The general arrange- 
ment of the collection is on the basis of geologic sequence, and 
is designed primarily to indicate the evolution of plant life from its 
earliest appearance on earth up to the present time. The best 
preserved specimens, or those which have some special signific- 
ance or are of value for general educational purposes, are displayed 
under glass, and the remainder are arranged in the tiers of 
drawers beneath the floor cases. 
There are now twelve floor cases and five wall cases, located 
in the main basement hall, to the east and west of the central 
part, and numbered in accordance with the geologic sequence of 
time and periods, as follows: (See Fig. 38.) 
FLOOR CASEs, 
No. 1— Paleozoic Time. Cambrian, Ordovician, Silurian, Devonian and early 
acticen Periods. 
2-4 — Paleozoic Time. Carboniferous Period. 
0. 5 — ozoic Time. Triassic and Jurassic Periods. 
Nos. 6-8 — Mesozoic Time. Lower Cretaceous Period 
9 — Mesozoic Time, er Cretaceous Perio 
No, 11 Neozoic Time. Tertiary Period (Eocene and Miocene). 
No, 12— Neozoic Time. Tertiary (Miocene), Quaternary and Modern Periods. 
WALL CasEs. 
No. 1— Paleozoic Time. Cambrian, Ordovician, Silurian and Devonian Periods. 
Nos, 2-4— Paleozoic Time. Carboniferous Period, 
No. 5—Neozoic Time. Tertiary and Quaternary Periods, 
A fair idea of the sequence of plant life in the history of the 
earth may therefore be obtained by observing the specimens in 
their sequence in accordance with the numbering of the cases, as 
indicated in Fig. 38. This, as previously stated, is a geolog- 
ical arrangement, but incidentally it is also roughly biological 
and follows the same system as that on which the museum of 
systematic botany is arranged, inasmuch as the plants of the 
earlier periods are low in the scale of life and those of the later 
