105
THE HABITS AND LIFE-HISTORIES
OF WOODLICE.
By WILLIAM HEELEY, B.Sc., Ph.D.
[Read 25th January, 1941.]
I. INTRODUCTION.
IT is now over thirty years since there appeared in the pages
of this Journal an account of British Woodlice by one of
the early members of the Club, Wilfred Mark Webb. This
account, together with his detailed descriptions and admirable
plates of the species then known, marked a decided advance in
the knowledge of this group of animals in this country, and, in
fact, still remains the only complete monograph on British
woodlice.
Subsequent workers have added further to the lists of species
which have been discovered in this country—notably R. S. Bagnall
who, in 1913, published an annotated list of the woodlice of
Northumberland and Durham, and W. E. Collinge, who com-
piled a revised Check-list of the British Woodlice in 1918, in
which the number of known British species had mounted from
the 25 listed by Webb to 35 ; but curiously enough, little more
appears to have been recorded during these thirty years on the
life histories and habits of woodlice. This appears all the more
surprising when one recalls that the commoner species of wood-
lice, or "sow-bugs," are continually being met with by naturalists
in search of other more favoured creatures, and are common
not only in our woods, but also in the neighbourhood of gardens,
greenhouses, outbuildings, and even dwelling-houses.
It may not seem untimely nor out of place, therefore, if
such notes as I have gleaned during the past few years con-
cerning the habits and life-stories of this insignificant but
nevertheless biologically important group of animals be similarly
recorded in this Journal, particularly since my investigations
were carried out in the same county and over much the same
area as that covered by Webb at the beginning of the century.
It may be as well to state at the outset, however, that my
observations were confined to the commoner species ; neverthe-
less, the members which I studied are such as are representative,