24 
Notices of Memoirs — J. S. Gardner' s Leeture — 
them attentively there is, it seems to me, a very well marked and 
recognizable sequence. I will now indicate the sequence. It 
has never been laid before the geological public until now, and it is 
possible, as is often the case with new work, that tbere may 
be some objections raised to it. I can only teil you, kowever, that 
after discussing the matter with geological friends, my own con- 
victions are strengthened.” The autkor then referred to his diagram 
of the district. “ This lower fresh- water series is seen in the neigk- 
bourhood of Corfe, and forrns part of the cliffs at Studland. It is 
ckaracterized by abundance of pipe-clays, and forms a thickness of 
possibly 200 feet. The middle fresh-water series, also met with 
near Corfe and at Studland, forms the wkole thickness of the cliffs 
between Poole Harbour and Bournemouth. We thus have a mag- 
nificent section four miles long and 100 feet in keight. Branksea 
Island is also formed of this series. Their entire thickness cannot 
yet be accurately estimated, but may be put down at some 300 feet. 
They are ckaracterized by the fact that the clays contained in them 
are usually brick-eartk. 
The next series above is a marine series, and is some 400 ft. or 
500 ft. thick. The base beds are dark sands and clays, succeeded by 
pebble beds and sands, then more sandy clays with pebbles, and 
ending with a thick deposit of white sands. This marine portion of 
the series occupies the cliffs between Boscombe and High Clifif. It 
is the middle fresh-water series which is so rieh in the clay beds 
containing fossil leaves. These leaves are found in various con- 
ditions of preservation. In most cases the impression only of the 
leaves in the clay is met with, but in some cases they are so well 
preserved that the actual substance has been retained, although Chemi- 
cal changes have altered its composition, and it will peel off and 
blow away. In some of the clays the masses of leaves are so decayed 
that they cannot be recognized, and are not worth our collecting. 
Where the preservation is good, we can readily distinguish the 
various original textures of the leaves by comparing their general 
aspect and colour both among tkemselves and with existing forms. 
For instance, those which are thick, such as evergreens ; thin, as 
convolvulus ; liard, such as oak ; or soft, such as lilac ; or even 
velvety, such as the common Phlox, can all be recognized. Their 
colours, in most of the beds, vary froni buff to brown, and I need 
kardly teil you that in no case have we any of the green colouring 
of the leaves preserved. Wkilst these various shades of dark bufifs 
and browns are in many cases the result of Chemical ckange that has 
taken place after the leaf was covered up, yet I believe that in many 
cases this change had occurred, at least partiallv, before the covering 
up, just as we saw a few weeks ago the changed colours of the fallen 
leaves of autumn. In the darker clays the remains are black and 
completely carbonized ; where this is so, the finer venation is iudis- 
tinct and the remains difficult to save, so that we may discard them 
unless the outline of the leaf is of unusual form. The darker browns, 
I take it, indicate hard and evergreen leaves ; for instance, the 
laurel-like leaves are always of a deep colour, whilst both the thin 
