380 
Mr. Norman H. Joy on the 
pure, sur laquelle on a projete de la poudre de Lycopode, 
on voit les spores fuir en arriere de I’aniinal et celui-ci 
laisser un large sillage, lorsqu’il vent fuir rapidement: 
aucune reaction ne se produit au contraire, lorsque I’insecte 
inarche simplement sur la surface. Si Ton d^tache 
I’extr^mit^ de I’abdoinen, on voit au bout de quelques 
instants celle-ci expulser par intermittence la sub.stance 4 
tension superficielle tres basse, et se mouvoir rapidement 
comme un morceau de camphre ou de thymol.” 
* * * * 
I have confirmed most of these observations with D. 
coerulescens and several species of the genus Stenus. My 
studies soon inevitably led me to the general study of the 
behaviour of Coleoptera during flood-time, as it must be 
chiefly at such a time that these powers of locomotion 
are brought into play. I have from time to time written 
notes on my observations which I hoped to publish when 
I had made a more complete study of the matter. How¬ 
ever, from want of time, little progress has been made 
during the last two years, so I think it best to publish 
them in the hope that they may stimulate others to con¬ 
tinue what is undoubtedly a very interesting subject. 
When flat land or a river valley is flooded by heavy rains 
it is well known that a very large number of beetles and 
other insects is to be found in the “ flood rubbish ” washed 
or blown up at the sides of the water. It is also notorious 
how very local are some of the beetles inhabiting the 
banks of streams, and one wonders how it is these species 
are not washed away at every flood, or at any rate 
scattered all down the valley. I believe that as a fact 
most beetles soon find their way to laud by various methods, 
and comparatively few, and those mostly of the larger 
species, get washed down the middle of the stream. 
This can be proved by examining flood refuse caught 
on bridges, etc., in mid stream, and that blown up at the 
sides of the river. In the former large beetles predomin¬ 
ate, very few small ones being found, whereas the latter 
generally teems with small insects. In some places the 
smaller beetles might be washed out of the mid-stream 
rubbish by the force of the current, but I have noticed 
that in the rubbish which collects over the arch of a bridge, 
when the whole arch is submerged, large beetles are found 
in greater numbers. It is chiefly due to the wind that 
the fine rubbish and small beetles so soon find the edge 
