1877.] Educated Fleas. 9 
employed in pulling, pushing, or carrying some object about. 
This portion of the exhibition is a genuine exposition of the very 
extraordinary strength in proportion to its size, which is pos- 
sessed by this little insect. Small and beautifully executed 
models of horse-cars, vessels, coaches, a wheelbarrow, butterfly, 
etc., are pulled about, each by a single flea attached firmly to a 
minute pole or wire, extending from or under the object. Small 
bits of silk, tissue paper or other light material are attached to 
the knot on the flea’s back, and by courtesy are termed dresses, 
or equestrians as the case may be. 
The proprietor states that the weight of a flea is about 0.05 of 
a grain, or, if well fed, 0.1 grain. He states that the model of 
the street car exhibited weighs one hundred and twenty grains 
or about twelve hundred times the weight of the flea which drags 
it. Whether these figures be precisely accurate or not, it is a 
very remarkable effort for so small a creature. Vigorous speci- 
mens are said to occur which are able to pull even a ee 
larger weight. 
The fleas from dogs are less strong than the human parasite, 
and require more frequent feeding. The ordinary flea will re- 
main four days, it is said, without injury for want of nourish- 
ment, and will live for weeks, though diminishing in weight. 
They are said to live about a year; the performers average eight 
months, but one is recorded by the proprietor as having lived 
twenty-three months in his possession, the last two of which were 
passed in a state of great weakness. 
It was noticeable that the surface over which the fleas dragged 
their burdens was composed of compact blotting paper on which 
their hooklets took good hold, and that whenever the perform- 
ance of any one individual was not going on, the particular ob- 
ject to which it was attached was laid on its side, or so that the 
insect was left, feet in air, where it could not exhaust itself by 
unnecessary efforts. I think that the absence of any proof of ed- 
ucation in the above cases is quite plain. 
In the second class of cases the efforts made by the flea to 
escape are precisely the same, but, being fixed itself, it must nec- 
essarily show its power by traction upon some movable grasa 
or by aimless gesticulations i in the air. 
Generally the insect is attached to a sort of style or wire- 
in a perpendicular position with the head uppermost and the 
limbs extended horizontally. Usually it will remain quiet, but 
if disturbed by the vibration of its wire, as produced by knoek- a 
