PROCEEDINGS-PERTHSHIRE SOCIETY OF NATURAL SCONCE. CV11 
past session, and that is the resuscitation of the “Associate” member¬ 
ship. In Perth, as in other towns, there are among the industrial 
classes many enthusiastic lovers of Nature who would wish to 
associate themselves with others of like tastes, but to whom even the 
moderate fees exacted by our Society bear rather too large a propor¬ 
tion to the weekly wage. To such students the Council were only 
too glad to open the door of our Society at a reduced fee of three 
shillings a year when the proposal w r as made to them. Already three 
most enthusiastic special meetings have been held, when the Associate 
Members and their friends have been addressed on scientific subjects 
by some of the older workers of the Society, and after each meeting 
the Museum has been eagerly examined. These new members are 
now looking forward to the summer, when it is intended to organise 
some special evening Natural History rambles in the neighbourhood 
of the city for their benefit. 
SCENES IN THE GEOLOGICAL HISTORY OF THE SITE OF PERTH. 
Leaving the practical affairs of the Society, I shall now occupy 
the few minutes remaining at my disposal by trying to call up before 
your imaginations some of the scenes to which the site of Perth 
has been witness in past geological times. In doing so I shall not 
paint any fanciful picture, but shall simply endeavour to interpret, 
from the present configuration of the landscape, some of the trans¬ 
formations which it must have undergone in past stages of the world’s 
history. Further, I shall only refer to those chapters in the history 
of which actual physical evidence may be seen in the district. There 
are some favoured spots on the earth’s surface, such as the Grand 
Canon of Colorado, where an unbroken succession of sedimentary 
rocks, extending through many consecutive geological ages, may be 
seen at one glance, but in no part of Europe is this the case. As 
a rule the record of the past has to be pieced together from memorials 
scattered over widely-separated areas. Especially is this the case 
in our own country, where the powers of nature have had full play 
in carrying away so large a proportion of the solid crust. Gaps in 
the record are thus created by the total destruction of whole series 
of rocks. Much vaster gaps, however, are probably due to the fact 
that for long periods our ancient Highland hills remained dry land 
while other parts of the Continent were submerged under oceans or 
vast lakes. It is impossible to say in the case of each gap to which 
of these two causes it should be assigned, but doubtless the latter 
one accounts chiefly for the fact that the great Secondary and 
Tertiary formations, which overspread the south and east of England, 
are only found fringing a few r isolated spots on our northern coasts. 
With these reservations in mind we shall now take up our position 
at some point, say on the ridge of Moncreiffe Hill, which commands 
both Strathtay and Strathearn, as well as the more distant view of 
the north, and shall try what fragments of the story of the past the 
surrounding landscape can teach us. 
Turning first to the north our eye travels over the undulating 
expanse of Strathmore to where the flanks of the Grampians begin 
