FACTS RELATIVE TO THE MOVEMENTS OF 
INSECTS ON DRY, POLISHED, VERTICAL 
SURFACES. 
—~<.——_. 
As objections have been urged against the opinion 
that flies and other insects of various species are 
enabled to move on the vertical surfaces of highly 
polished bodies by the emission of an adhesive fluid 
from the numerous hair-like papille distributed over 
the inferior surface of their pulvilli, the statement of 
a few plain facts for the consideration of dissentients, 
and especially of those who still advocate the hypo- 
thesis that flies, in such instances as those referred to 
above, are supported in their movements mainly by 
the pressure of the atmosphere, may, perhaps, be 
deemed deserving of attention. 
Without the slightest intention to undervalue the 
importance of microscopic researches into the organi- 
zation of the parts in question, I may be permitted 
to remark that the careful observation of phenomena 
and judiciously selected and skilfully conducted ex- 
periments afford equal if not superior advantages 
with regard to the determination of the function they 
perform, and that the two methods of investigation 
