5B 
to discovering other forms of life, bid, witliout result. The decaying 
props, with fungus, an occasional diet of a cannabalistic nature, and 
such other animals as may he introduced and die in the pit, and 
perhaps, especially insects and rodents, are what suggest themselves 
as their food, 
I set out, however, with the intention of showing how the 
crustacean had got -into the pit. A resident of Blyth, tamilar with 
the changes which that town has undergone during the last gener- 
ation, would doubtless have been able to have solved the problem 
with greater ease had he known also something of the habits of 
Oiimmants duebeni. I spent some time to begin with examining the 
river Blyth, from above the harbour to Bebside, and I was surprised 
and disappointed not to find this species in the situations which 
appeared to be quite favourable, and I was only successful in obtain- 
ing one specimen of Gammarus camj>ylops. When I had got thus far, 
1 only learned by accident that the Mill Pit was sunk on the edge of 
an extensive slake and that the slake had been filled in, and the 
place now occupied by houses and streets. That such a slake would 
have been an ideal habitat for Gammarus duebeni goes without saying. 
Some cmpiiries yielded the further information that the slake com- 
municated with the river at the place now occupied by the lower dry 
docks, and that on being reclaimed a drain was made which ran 
through the place occupied by the slake and opened where the latter 
joined the Blyth ; and that moreover it received two ditches, one of 
which runs past the pit where it also joins the other. 
I was able to pay the pit a visit once more on September 11th, 
and I then found in the ditch first mentioned above, Gammarus 
duebeni along with the 8-spined stickleback. There is no doubt ihere- 
fore that both these forms have been carried into the pit at times 
when floods have occurred, that the sticklebacks have died, but the 
gammarids were able to accomodate themselves to the new habitat, 
and survived, and this meant accustoming themselves to absence of 
light and to a practically new" and more than probably scanty food. 
The pit was flooded three years ago, and a previous flood occured 
as far back as 1887, i.e., sixteen years since, when the pit in fact was 
not quite completed. It is more than likely therefore, that the Gam- 
marus duebeni w"as introduced in 1887, and received an accession in 
1899. 
For the information which led to the solution of the interesting 
problem, I have to thank Aid. Dent, Mr. Albert Ward, and Mr. 
Saimders. 
