499 
of Edinburgh, Session 1868-69. 
large mass of data from which the origin of the present outlines of 
the country may be deduced. These data are published upon the 
maps and sections. They seem to me to prove irresistibly the truth 
of the doctrine, which was first propounded within the walls of this 
Society by Hutton, that the existing contour of the land is not to be 
traced back to the operation of earthquakes, upheavals, and depres- 
sions, but mainly to the eroding influences of rain, springs, rivers, 
ice, and the sea. In illustration, I would point to the map sus- 
pended upon the wall, and show how the lines of large fracture 
ascertained by the Geological Survey are not marked at the surface, 
as a general rule, by any corresponding valley or depression ; while, 
on the other hand, the existing valleys and ravines, instead of coin- 
ciding with lines of fault, as is too often assumed, in reality run 
across these lines in all directions, and without any reference to 
them at all. It must be a subject of congratulation among the 
Fellows of this Society to find that the views propounded here by 
their illustrious predecessor Dr Hutton* after being almost lost 
sight of for more than half a century, are now everywhere gaining 
ground rapidly, and that there is a growing recognition of the genius 
of that great man. Hutton, as it appears to me, is the true father 
of modern physical geology. Only now are we coming abreast of 
him, so far was he in advance of his time. 
The following Communication was read : — ■ 
On Traces in the Adult Heart of its transitions in form 
during Foetal Life. (Part I.) By P. D. Handyside, M.D. 
(With a Plate.) 
In this paper the author described in the adult human heart 
certain vestiges of structures which, during fcetal life, exist in an 
entire and perfect state. At birth, however, these, ceasing to be 
of use, generally disappear. 
In allusion, first , to the Eustachian valve, he exhibited (and 
illustrated by the annexed sketch, fig. 1), an apparently unique 
specimen — obtained in his dissecting-rooms about six years ago — 
namely, a very large and reticulated Eustachian valve, prolonged 
at its middle third in the form of a semi-insulated cribriform fibrous 
