May 17, 1901.] 
than to the left, so that qualitatively it will 
be perceived as different from the same 
sound when heard directly in front. In 
the case of monaural hearing it is clear that 
the intensity of a sound can afford only the 
most ambiguous information. An apparent 
change in intensity in such a case may 
mean change of distance, change of direc- 
tion, change of actual intensity or some 
combination of these alternatives. But the 
single ear is by no means so helpless as re- 
gards the detection of qualitative differ- 
ences due to changes of direction. Our 
subject himself connected his capacity to 
localize sounds with this noticed change in 
quality. His results show that (although 
in every case he remained ignorant of his 
success or failure during the experimenta- 
tion) he possessed to begin with a relatively 
accurate auditory orientation on the basis 
of these qualitative peculiarities of sounds 
due to their direction, and, furthermore, 
that after gaining a little familiarity with 
the sounds, his localizations became very 
accurate. Nor did he seem to find any 
serious difficulty in determining direction, 
when the absolute distance of the sounds 
was varied, nor yet when the absolute in- 
tensity was varied. Pure tones he could 
not localize for they undergo no qualitative 
modifications by change of direction. In- 
tensity changes are the only ones of which 
they are susceptible. Slightly complex 
sounds he can localize fairly. Highly com- 
plex sounds, possessing component tones 
well inside the range of ready detection, he 
can localize extremely well, save in the 
region just opposite the deaf ear. The 
same statements hold for localizations 
above and below the equatorial plane, to 
which we have confined our description. 
The modifications met with outside this 
plane are all conformable to the funda- 
mental theory of the dependence of the 
localizations upon qualitative differences in 
the sounds. The pinna, the meatus, the 
SCIENCE. 
ra 
bones of the head, etc., all contribute to 
the production of these qualitative modi- 
fications. 
JAMES RowLaAnp ANGELL. 
THE UNIVERSITY OF CHICAGO. 
FOOD OF SEA LIONS. 
TuE California State Board of Fish Com- 
missioners during the past two years has 
taken steps to kill off a very large number 
of sea lions on the California coast, on the 
ground that these animals are highly de- 
structive tothe salmon fishery. The presi- 
dent of the board, Mr. Alexander T. Vogel- 
sang, claims that it is not the intention of 
the board to exterminate the sea lions, but 
merely to kill ‘10,000 of the 30,000 that 
now infest our harbor entrance and contigu- . 
ous territory.’* The opinion of observers 
familiar with the sea lion rookeries is that 
the number of animals has been greatly ex- 
aggerated, and that long before Mr. Vogel- 
sang has killed the contemplated 10,000 
there would not be a living sea lion left on 
the whole coast. Already many have been 
killed and, unless public sentiment is 
aroused to check the movement, some of 
the most interesting rookeries of the State 
are in danger of depletion. The Fish Com- 
missioners have employed men to shoot the 
sea lions, and are loud in their lamentations 
because the Government light-house reser- 
vations have not been thrown open to the 
slaughter. . 
The local fishermen, the State Fish Com- 
mission and others assert without qualifica- 
tion that the sea lions feed extensively on 
salmon, and the inference from their state- 
ments is that the animals subsist chiefly, if 
not entirely, on fish. A few years ago, 
when similar complaints were made against 
the fur seals, I took the trouble to examine 
the stomach contents of a large number of 
these animals, and found to my surprise 
*In letter to Hon. Lyman J. Gage, Secretary of 
the Treasury, dated San Francisco, June 3, 1899. 
