of Edinburgh, Session 1868-69. 
531 
associated beds, as well as the nature of the animals whose bones are 
found in it and in these beds, shows that at this epoch the climate 
of North-Western Europe was arctic; and the height at which 
shell beds of that period, as well as other marine strata, have been 
found, shows that Scotland must have sunk to the depth of at least 
3000 feet below the present sea-level. 
When the land was so submerged, icebergs came over the sub- 
merged land, and grating upon the sea-bottom, converted many of 
the beds into boulder-clay. 
The phenomena of smoothed ridges and water sheds, the posi- 
tion of blocs perces, and the transport of boulders generally, can be 
better explained by floating ice than by glaciers. 
8. The arctic climate of North-Western Europe was probably 
caused — (1.) By the Gulf-Stream flowing in some other direction 
than that now followed by it; (2.) By an arctic current flowing 
from the west or north-west ; (3.) By the existence of high land 
in the North Atlantic, which increased the cold, produced glaciers 
and icebergs, and gave an easterly or south-east direction to the 
arctic current. 
4. On the Development of the Flower of Pinguicula vulgaris, 
L., with Remarks on the Embryos of P. vulgaris, P. 
grandifora, P. lusitanica , P. caudata * and Utricularia 
minor. By Alexander Dickson, M.D. Edin. & Dublin., 
Regius Professor of Botany in the University of Glas- 
gow. 
The affinities of the order Lentibulariaceee having hitherto been 
somewhat obscure, the author undertook the investigation of the 
floral organogeny of P. vulgaris, in the hope of being able to throw 
some light on the subject. 
A plant of P. vulgaris , examined during the flowering season, 
exhibits a short axis with “ radical ” leaves spreading as a rosette, 
and terminated by an unstalked umbel of ebracteate flowers. In 
the axil of the last leaf is produced a bud, which, after the matur- 
* The observations on the embryo of this species were made after the paper 
had been submitted to the Society. 
