AveustT 30, 1918] - 
pressing them down to the table with a strok- 
ing movement. The unclipped flies did not 
do this, and since they appeared entirely nor- 
mal I allowed them to escape. 
The clipped flies continued stroking their 
bodies and would not attempt flight except 
when provoked by being touched with a piece 
of paper which I pushed under the jar. Then 
their flight was extremely erratic. They 
seemed to have largely, if not wholly, lost their 
power of equilibrium. They would fall up- 
side down, and could pursue no direct flight 
at all. 
As a further test I left them under the jar 
until the following day and repeated observa- 
tions with the same results. I again put some 
normal flies in a jar besides the clipped ones 
to compare action in flight. The unclipped 
flies had no difficulty in maintaining an up- 
right position while flying about the jar even 
though they were striking the sides continu- 
ously. The unclipped flies stayed in flight 
much more, and without provocation. 
As a final test I took the clipped flies out of 
the jars and let them go. Although the move- 
ments of the wings appeared entirely normal 
they could not fly, but fell to the floor with an 
erratic zigzag movement. 
Experiment 2—The procedure in this case 
was the same as in the first experiment, ex- 
cept that I used five flies instead of two. For 
each fly that I clipped I imprisoned another, 
unclipped, that had been subjected to ether for 
the same period, to use, as in the first experi- 
ment, for comparative study. The five from 
which I removed the balancers I put under one 
jar. The other five I placed in a second jar 
beside the first. 
These flies I allowed to remain under the 
jars overnight in order to recover completely 
from the effects of the ether. On the follow- 
ing morning I found that one of the flies that 
had been clipped had died; two of the un- 
clipped had succumbed. Probably the dose of 
ether had been too great. 
Upon testing their powers of flight I found 
that the clipped flies, just as in the first ex- 
periment, were altogether unable to maintain 
equilibrium. Not one of them when released 
SCIENCE 
223 
could fly at all, but dropped to the floor with a 
zigzag darting movement. The unclipped flies 
flew off in normal flight. 
Experiment 3.—Having acquired considerable 
skill at removing the balancers I put a large 
number of flies under the anesthetic at once. 
Then from nine flies I removed both balancers 
and placed them all under one jar. From 
eight flies I removed one balancer and put 
them under a second jar; and finally I put 
seven flies under a third jar. These seven had 
been subjected to the same dose of ether, but 
I left them untouched and confined them for 
comparative study as in-the other experiments. 
The results accorded exactly with those of 
the other tests. 
(a) Flies seemed to notice the removal of 
the balancers, and kept stroking themselves 
with their legs about the wings and abdomen. 
(b) In no ease was a fly with both balancers 
removed able to fly. They could use their 
wings, but had no power of equilibrium. 
But in contrast to this, the flies with only 
one balancer removed could fly without diffi- 
culty, in a manner to all appearances perfectly 
normal, although sometimes I thought they 
had slight difficulty in gaining balance at the 
commencement of a flight. 
From these experiments I concluded that 
the balancers of the fly are intimately con- 
nected with his nervous system, and by a dis- 
tinct and essential function enable him to 
maintain equilibrium in flight. But just as a 
man is not deaf who has one ear injured, nor 
blind though one eye is destroyed, so this 
power of equilibrium is not essentially im- 
paired without the removal of both balancers. 
Submitted November 8, 1917. 
Rowan WHEALDON 
QUOTATIONS 
THE PROPOSED BRITISH’ MINISTRY OF 
HEALTH 
Tue Ministry of Health Bill, which has been 
under the consideration of Sir George Cave’s 
Home Cabinet, will not, we imagine, prove to 
be a measure as comprehensive and revolution- 
ary as recent debates and discussions might 
lead the public to suppose. In this connection 
