Mr George Logan on Fossil Plants. 367 
according to the way in which the cart was turned in throw- 
ing them out. The metal upon a macadamised road also 
shows the same arrangement. 
The currents of the atmosphere likewise exhibit the same 
phenomenon. As is well known, the storms of southern 
latitudes revolve from left to right, whilst those north of the 
Equator revolve in an opposite direction. These revolving 
storms, to which the term " cyclones" has been applied, 
appear to be truly of spiral form. This has been all but 
demonstrated by the able and laborious researches of Mr 
Buchan, secretary to the Scottish Meteorological Society, 
{vide his paper in the " Transactions of the Eoyal Society 
of Edinburgh," read 3d April 1865), and will probably be 
soon placed beyond a doubt. 
It is not the object of this short paper to enter into any 
investigation as to the exact manner in which the spiral 
forms in question are produced, but simply to call attention 
to a subject which seems, so far as the author is aware, to 
have been overlooked by even the most acute observers of 
physical phenomena, but the study of which will be found 
highly interesting as well as instructive. 
(2.) Mr George Logan exhibited specimens of Fossil Plants from 
the Upper Old Red Sandstone, near Dufise; with Notes hy William 
Stevenson, Esq., Dunse. 
The two specimens of vegetable fossils exhibited are from 
the Upper Old Ked Sandstone of Prestonhaugh (between 
two and three miles north of Dunse). In the same beds a 
fine specimen of the Gyclopteris Hihernica was found a few 
years ago by Mr Stewart, Edinburgh, who presented it to 
Hugh Miller, in whose collection I saw it shortly afterwards. 
Though common in the Irish Devonian strata, I believe 
that no other specimen has been found in Scotland. In the 
Prestonhaugh beds are many obscure vegetable remains, ap- 
parently fucoids, some of large size. Associated with these 
are remains of the Holoptychius nohilissimus, Ptericlithys 
major, &c., characteristic of the Upper Old Eed. Several 
of the strata are beautifully rippled, and some show cracks 
