1 82 Reid.— Notes on the Geological History 
truly natives of Britain now, if such really be the case. Still, 
it must not be forgotten that the occurrence of a plant in these 
interglacial beds, does not prove that it ought to be accepted 
as a native of this country in postglacial times, though it may 
be good evidence that it was not first brought to this country 
as a weed of cultivation. Between the interglacial and post- 
glacial periods there occurred a period of glaciation, during 
which a large portion, probably most, of the native plants were 
exterminated, to be reintroduced when the climate ameliorated. 
The peaty bed from which the plants were obtained in the 
neighbouring quarry of Hailes, though probably of about the 
same age, does not now lie under boulder clay. However, in 
a letter dated September 28th, 1887, Mr. Bennie writes that 
‘ Hailes quarry is very large, and in the south side of it a few 
years ago there was exposed a peat bed interbedded in 
boulder clay, as described and figured in “Prehistoric Europe” 5 
[by Prof. James Geikie]. The occurrence of Salix herbacea 
and abundance of Isoetes , neither of which are found in the 
neighbourhood now, shows that the peat is, at any rate, no 
modern deposit, and I think it may be classed provisionally 
with the interglacial beds. It is unfortunate that the bed of 
peat actually tinder boulder-clay is not now visible, and can- 
not be searched for plants. 
Mr. Bennie has sent me twenty-five species of flowering 
plants from Hailes, besides several still undetermined. With the 
two exceptions already mentioned, they are species still found 
in the lowlands, though the absence of all, except such as 
have a considerable northward range, is suggestive of a climate 
somewhat colder than that of the south of Scotland at the 
present day. The flora of the extreme north of Scotland is 
more similar. 
A similar peaty bed between two masses of boulder-clay 
has recently been described by Mr. Robert Dunlop, as occur- 
ring at Airdrie, near Greenock 1 . Through the kindness of 
Mr. Dunlop and Mr. Bennie I have been able to examine the 
plants, but find the flora is poor, the majority of the specimens 
1 See Trans. Geol. Soc., Glasgow. 
