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PROCEEDINGS OF THE PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
August 8th. 
6. To the Linn of Campsie, 
The neighbourhood of the Linn of Campsie is not only a 
good field for the botanist, but presents some interesting 
geological features. As is well known, the Linn is formed 
by a large trap “ dyke,” which here stretches across the 
Tay. From the low condition of the river, the party was 
able to examine much more of the dyke than usual, and to 
investigate several curious “pot-holes” that are usually 
covered with water. “ Pot-holes," it may be explained, 
are circular excavations in the solid rock, and are formed 
by the current revolving a hard stone or stones in them. 
Occasionally they are of great size and depth. Another j 
point of geological interest to be seen at the Linn (but { 
better near a smaller dyke a few yards south of it) is the 
alteration in the Old Bed Sandstone rock caused by the heat 
of the molten rock that pierced it to form the “ dyke.” In 
some places the sandstone is quite friable in consequence; 
in others it has been rendered harder than usual. Leaving 
the geology, attention was directed to the botany of the 
locality, and a number of interesting plants found and 
examined. Amongst these were Veronica anagallis, 
Potentilla procumbens, Alchemilla alpina, and others. 
Leaving the Linn, the party next crossed the river, and 
descended the east bank. The most interesting plant 
found here was one of the Bell-flowers, Campanula glome- 
rata, which only one of the party had seen (as a wild 
plant) in Perthshire before. Don, the well-known early 
investigator of Scottish botany, records the plant as from 
“ near the Linn of Campsie,” as long ago as 1806; and the j 
Kev. Mr Liston mentions it as growing on the banks of 
the Tay in Redgorton parish in 1837: but since that time 
it has been either overlooked or passed by as an introduced 
plant. It, however, has all the appearance of being truly 
native, and as such we accept it. It occurs along the 
banks for several miles. 
Near the “ Cat Hole” another rare Perthshire plant was 
found—the Hemp Agrimony (Eupatoriurn cannabinum). 
Passing on to that wild part of the river which rejoices 
in the euphonious and very appropriate name of “ Hell’s 
Hole,” the margin of the water had to be left and the rocks 
ascended. Hence, looking down on the black abyss below, 
Virgil’s “ Facilis descensus Averni ” readily suggested 
itself to the classical mind of the beholder. Near this, 
several specimens of the rare and curious bird's nest orchid 
(Neottia nidus avis), were found. This plant is of a pale 
brown all over and has no true leaves, deriving its susten¬ 
ance from the decaying vegetable matter amongst which 
it grows. After passing the ruins of Cambusmichael 
Church some of the party crossed the river and returned to 
Stanley, while the rest followed the Tay down to Perth and 
added several other interesting plants to their collection. 
August 22nd. 
7. To North Bank of Earn, from Forteviot downwards. 
Starting from Forteviot Station, the party explored (by 
the kind permission of Lord Kinnoull) the north bank of 
the Earn, and adjacent “ back-waters,” nearly as far as 
Forgandenny. After that point the river was left, and 
the hill road to Perth taken. 
Amongst the more interesting plants observed may be 
mentioned that curious orchid, the broad-leaved helle- 
borine (Epipactis latilolia); the pretty red-flowered 
Erytlwcea centuarium, a plant very local in Parthshire; 
the yellow-flowered Limuanthemum nympheeoides; Car ex 
paludosa and C. remota; and a number of curious willows. 
The zoologists of the party had nothing remarkable to 
report. 
