190 
Psyche 
[March 
effected by first immersing them in cold ( — I95°C) liquid Freon 
(while held in forceps to cause eversion) and then transferring them 
to a tissue freeze-dryer for desiccation. 
Instruments for chemical analyses included conventional gas chro- 
matographs and an LKB-9000 gas chromatograph-mass spectrometer. 
Sound recordings were made at 23-25°C with a condenser micro- 
phone from a Holgate Ultrasonic Receiver MK.V [frequency re- 
sponse ± 12 db from 1 to 100 kHz; sensitivity at preamplifier out- 
put 268 mv (rms)//ibar at 60 kHz (determined by substitution)], 
an Ithaco Amplifier Model 225 [variable amplification range from 
O to 80 db; flat frequency response (within 3 db) in range of 0.5 
Hz to 100 kHz] and a Lockheed Magnetic Tape Recorder/Repro- 
ducer Model 419 [recording speed set at 30 inches/sec; flat fre- 
quency response (within 3 db) in range from 0.2 to 100 kHz; input 
sensitivity of 1.4 volt (1.0 volt rms) for ± 40% deviation]. Sound 
intensity was measured with a Briiell and Kjaer Precision Sound 
Level Meter Type 2203 and a Briiell and Kjar Condenser Micro- 
phone Cartridge Type 4145. The intensity measurements were 
limited to audio frequencies due to limitations in the frequency 
response of the Briiell and Kjaer Microphone [flat frequency re- 
sponse (within 2 db) in range from 2.6 Hz to 18.5 kHz]. 
Instruments used for displaying and recording temporal patterns 
of the sound included a Tektronix storage oscilloscope (Model 
4103N) with differential amplifier (Model 5A22N) and Polaroid 
camera, and a Tektronix dual beam oscilloscope (Model 502 A) with 
a Grass Kymograph camera (Model C4N). Timing marks were 
generated on the oscilloscope with a Hewlett-Packard function gen- 
erator (Model 3310A). 
Sound spectograms were made with a Kay Elemetrics Sonograph 
(Model 7029A). Low frequency background noise was filtered as 
needed during playback of the recordings with a Krohn-Hite filter 
(Model 3550). 
Chemistry of the Secretion 
It was clear from the outset that the secretion of both species was 
quinonoid in nature. The beetles responded typically to rough hand- 
ling by protruding their glands, and the oily golden-brown fluid that 
visibly coated the everted structures had the unmistakable pene- 
trating odor of benzoquinones, and the characteristic quinonoid 
