832 The American Naturalist. [September, 
is identical with the impulse to activity of its antagonist, was thus 
excluded. The subject of the experiment contracted or relaxed his 
masseter muscle upon feeling an electric stimulus upon the wrist, the 
movements with time curve being recorded upon a revolving drum. 
The results show practical equality in the two forms of will activity 
{e.g., the contraction reaction time=.i5 sec, the relaxation reaction 
time=.i4 sec), the slight differences being attributable to the method 
of experimentation. Exercise shortens both; increase of intensity of 
stimulus shortens both alike ; both are similarly affected by alteration 
in the intensity and amplitude of the muscle contraction ; alcohol at 
first shortens, then lengthens both ; in short, the experiments argue 
against the dualistic theory of the two processes. If then voluntary 
impulses and inhibitions are physiologically identical, the anatomical 
localization of the interference of the two processes must be in the 
psychomotor centre. The effects of attention were studied, but have 
not yet been completely formulated. 
PSYCHOLOGY. 
History of the Owl, continued. — To the readers of the Ameri- 
can Naturalist it may not be amiss to know something more of the 
final history of the two owls, the great horned and the barred, whose 
habits were described in the January number. 
The lively disposition of the "bubo " increased as he grew older, 
and at times he would jump and fly about his room with a waggish air 
that was very amusing. 
The Syrnium, on the contrary, became more sullen and morose, and 
seemed to be constandy in the " sulks " about something. 
Their combined hootings at early dawn and twilight were music 
indeed to the ear of a naturalist. Cloudy days or an approaching 
storm would also excite the barred owl into uttering his peculiar notes; 
his mate not infrequently joining in the chorus. 
One day in March, while driving on the prairie, I shot and winged 
a fine specimen of the American rough-legged hawk {Archibuteo lago- 
pus sanctijohannis). Not having time that day to make a specimen of 
him, I put him for safe keeping in with the owls. The next morning, 
upon presenting myself at the door, I was greeted by a regular pande- 
monium of hoots and screeches, which at once struck me as presaging 
no good to my hawk, and, in fact, the latter was nowhere to be seen. 
