364 NEW PUBLICATIONS. 
It is perhaps a matter of surprise, that during the many years 
whieh have elapsed since geographical botany put in a claim to be 
ranked as a distinet department of science, a detailed Flora of the 
county has not been before attempted; considering the interest 
which it possesses in showing, not only how the character of a 
flora is modified by human agency, but also as bearing upon the 
history of the gradual growth of London, and the history of British 
botany and British botanists. But it is easy to see that with- 
out a large amount of labour incurred in gathering together and 
arranging the old records, the work could not be adequately done. 
This the authors of the work before us have thoroughly understood, 
and they have been willing, in gathering them from all available 
sources, published and unpublished, and carefully sifting them, to 
spend an amount of pains and labour which certainly merits for them 
the thanks of all who are interested in English botany. A great 
part of the value of their work arises from the fact that they have 
been able to see so well that, Middlesex botany possesses in this way 
a unique interest of its own, and that instead of merely following 
in the track of those who have written county Floras before them, 
they have not spared to spend the unusual amount of labour that 
was necessary to develope to the full the historical interest of the 
subject ; and it makes their book, over and above its value as a record 
of stations and distribution, one that can be read with pleasure and 
instruction by those who take no special interest in botanical details. 
The first part of the book is devoted to a sketch of the physical 
geography, geology, and climate of the county, and is illustrated by 
a coloured map, showing the area occupied by the different strata and 
the boundaries of the seven districts, founded on river-drainage, through 
which the dispersion of the species in the body of the work is traced. 
. Along the northern border of the county the ground rises into a ridge 
that for several miles reaches a height of between four and five hundred 
feet above sea level. A similar ridge of equal height bounds London 
on the north at Highgate and Hampstead. Between the two is a de- 
pression, out of which rises only the isolated hill on which the village 
of Harrow stands. The south-western third of the county is a low fiat, 
nowhere more than twenty feet above the Thames level at Staines. In 
the character of the soil, we get in the county two well-marked divi- 
sions, underlaid by beds differing but slightly in age but materially in 
