PROCEEDINGS OF THE PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
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arranged on tables running across the room, and also on 
the platform. These included the instruments belonging 
to the Society, besides a number which were kindly lent 
by members; and they varied in power from i to 2 inches. 
The objects exhibited represented a wide range of micros¬ 
copical research, and included many specimens of great 
interest. The different sections were under the charge of 
the following gentlemen:— Entomology, Mr Magnus Jack- 
son, Perth; and Mr Marshall, Stanley. Physiology and 
Pathology, Mr James Stewart, Perth. Botany, Messrs 
James and Henry Coates, Perth. Infusoria, Messrs 
Robertson and Wood, Blairgowrie. Rotifera, Mr Wood, 
Blairgowrie. Chemistry, Mr Keith, Perth. Geology, Mr 
Mackay, Perth. Astronomical photographs taken from 
nature were exhibited by Mr D. M‘Lagan, Perth, and 
Chromo-lithographs of several of the slides shown were 
exhibited by Mr R. D. Pnllar, Perth. The changes of 
colour in chemical crystals and in sections of crystaline 
rocks were exhibited by the aid of the polariscope. The 
circulation of the blood in a frog’s foot, and also the sap 
circulation in plants (cyclosisj, were shown to great advan¬ 
tage. The Museum was also open to the inspection of 
the public, and was largely taken advantage of. The 
whole arrangements, which were of the most complete 
description, were under the charge of Mr John Campbell^ 
optician, High Street. 
May 3rd, 1883. 
Hugh Barclay, Escp, LL.D., in the Chair. 
NEW MEMBERS. 
The following were elected Dr Eerguson; Rev. David 
Macfarlane; MrsStruanRobertson; MrP.Wilson, Leonard 
Street; Mr Carnochan, Superintendent, Perth Cemeteries; 
Mr A. Heiton, architect; Miss Eorbes, Athole Street. 
The following were nominated for election at next meet¬ 
ing :—Miss Burton, Marshall Place; Mr J. S. Imrie; Mr 
H. H. Greig; Mr P. Strang, jun„ chemist; Mrs Roy, 
Craigclowan; Mr Alex. Murray; and Mr A. H. Lumsden, 
Superintendent of Fisheries. - 
DONATIONS. 
The following donations were intimated:—Coot—Mr J. 
Pearson, gamekeeper, Methven Castle; carp —Mr Speedie, 
St John Street; coot, dabchick, and amliurst pheasant— 
Mr D. M. Smythe, yr. of Methven; sparrow-hawk—Mr 
Young, Freeland ; owl—Mr W. Campbell, Blair-Athole ! 
peregrin falcon—Mr Stewart, Logiealmond; 14 gull’s eggs 
—Mr Scott, Methven Castle ; pair bullfinches—Mr W. 
Campbell, Blair-Athole; dipper’s nest and eggs—Mr P. D„ 
Malloch, Perth. 
The following paper was read :— 
“ Mimicry in Insects .” By Mr S. T. Ellison. 
The term “mimicry” has been adopted by natu¬ 
ralists, in place of any other more applicable, to denote 
those cases which are to be found throughout the animal 
world where advantages accrue to certain animals on 
account of their colours, either resembling other animals 
which have for various reasons immunity from danger, 
and thus the former share in the advantages possessed 
by the latter; or else they derive benefit by their 
colours harmonizing with their surroundings. Some 
have restricted the application of the term to those 
only which imitate other animals; but in asking your 
attention to-day for a short time to the consideration 
of a few cases of mimicry in insects, I shall make use of 
the term in its widest sense, including within its range all 
the various aids to protection—whether of form, of colour, 
or of action, either singly or combined—by which insects 
are enabled to hold their own against and overcome the 
many dangers to which they are exposed, believing that it 
is as much mimicry when an insect, by its form, resembles 
a twig, or when an insect, by its action, feigns death, as it 
is in the case of those insects which, by their colours, 
imitate other insects of widely-separated orders. The 
principal objection to the term is that, at first sight, one 
might suppose that the animal possessing the advantages 
referred to resorted to and used them consciously for its 
protection—a definition I do not think any one would 
agree to accept. Of course, in those cases where the 
actions of insects aid or add to their protective appearance, 
I think we must admit a certain amount of instinctive 
consciousness,—cases of which I shall mention further on. 
The prominent position attained by these mimetic resem¬ 
blances in so many cases is no doubt owing to the selection 
and continuance of those forms which have afforded the- 
most perfect freedom from danger, and by the eradication 
of those which have presented points of weakness. 
The dangers to which insects are exposed may be included 
under two heads—first, danger of perishing from lack of 
food; and, secondly, danger from being made food of by 
