84 
PROCEEDINGS OE THE PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
tional. Specimens ought to be arranged systematically, 
and bear more or less instructive labels. But beyond this 
something more was required in the way of an introduction 
or guide to the system of arrangement adopted, and it was 
with the view of supplying this that the author had been 
induced to prepare this paper. 
As had been frequently stated befoi e, the Museum con¬ 
sisted of two departments. One—the larger—was con¬ 
fined solely to the natural history of Perthshire and 
the basin of the Tay; the other was intended to form, 
as it were, an introduction to that, by showing in a 
small space what the scheme of creation, as interpreted 
by naturalists, was throughout the world. In the Perth¬ 
shire collection the Society hoped eventually to bring 
together specimens of every animal, plant, and mineral 
that was to be found within the district; to classify them; 
and to label them in such a manner that as much instruc¬ 
tion as possible might be conveyed to the student. This 
department, though the more important, and to naturalists 
in general the more interesting, required to be supple¬ 
mented to carry out the scheme of making the Museum as 
powerful an instrument of education as possible. Perth¬ 
shire, though no doubt large in their eyes, was after all 
but a very small part of the world; and its fauna and flora, 
though extensive, required supplementing if they were to 
show clearly the system of classification in natural history. 
They had, therefore, added to the Museum, but kept dis¬ 
tinct from the Perthshire Collection, another collection, 
which might be termed the “ Typical” or “ Index Collec¬ 
tion,” which consisted of a few carefully-selected types of 
orms illustrative of every chief group in the animal, 
vegetable, and mineral kingdoms. The “Typical Collec¬ 
tion ” was contained in four table cases. These gave an 
area of about 174 square feet,—not very much in which to 
Illustrate the subject, but still enough in which, with 
careful selection, a good deal could be done. 
The first table case was devoted to geology, and one side 
of it was occupied by illustrative examples of minera¬ 
logy. The arrangement followed in this department 
was that of Dana’s “ System of Mineralogy.” Dana, in 
the last edition of his work, gave about 900 species or 
forms of minerals, and, as illustrations of these, the 
Society had upwards of 300 specimens (some of them con¬ 
sisting of several examples) selected from the more im¬ 
portant forms, and forming as good a typical collection of 
minerals as could be desired. In the labels attached to 
each the following particulars were given :—First, the 
name of the mineral; second, its crystallization (if crystal¬ 
line); third, a brief indication of its chief constituents; 
and, fourth, the locality whence the specimen was derived. 
In selecting the typical minerals for this collection special 
attention had been given to the minerals more specially 
characteristic of the rocks to be found in Perthshire, 
though, of course, other important minerals had not been 
overlooked. 
The other half of the table-case was occupied by 
a collection illustrative of petrology as distinguished 
from mineralogy. In other words, it was designed to 
show types of the chief rocks of which the crust of the 
earth was composed. The term "rock” was not, in the 
vocabulary of the geologist, restricted to the hard, stony 
formations which in common language were so called, but 
was applied to all the different layers, hard or soft, which 
went to form the earth’s surface. Thus clay, sand, or 
gravel were geologically rocks. 
In the next table-case there were a large number 
of specimens illustrating by characteristic fossils 
the stratigraphical arrangement of the sedimentary 
rocks. They also served to show the successive develop¬ 
ment of animal and plant life on the surface of the 
earth. These fossils—of which they had upwards of 
300 kinds, and many examples—were arranged to show 
the order in which the rocks succeeded each other. 
Having arrived at the end of the geological portion of the 
typical collection, they passed on to the cases containing 
illustrations of zoology or of the animal kingdom. The 
organisms which in classification went to form the animal 
kingdom were portioned out into what were termed sub¬ 
kingdoms, of which the lowest contained the animals 
which approached in structure the lowest representatives 
of the vegetable kingdom, and the highest those animals 
which possessed a backbone. The lowest sub-kingdom was 
that of the Protozoa, the boundary line between which and 
th e vegetable kingdom was so vague and shadowy that it was 
a matter of opinion whether certain organisms sometimes 
placed in it were animals or plants. The great majority of 
the Protozoa were of minute size, and lived either in salt 
or fresh water: and as it was impossible to show speci¬ 
mens of the creatures themselves, they would be repre¬ 
sented by drawings or models, or, in the case of the shell- 
bearing groups, by their shells. The illustrations at 
present consisted of drawings of animals—very much mag¬ 
nified—belonging to the sub divisions of each of the three 
great classes into which the sub-kingdom had been divided. 
The second sub-kingdom was that of the Ccelenterata. 
The animals belonging to it were all aquatic, and had, un¬ 
like the Protozoa, a distinct body cavity, but they had no 
proper intestinal canal. These would be illustrated by 
means of models, the group being a very difficult one to 
illustrate by the animals themselves. 
