10 
Psyche 
[March 
ORB WE AVERS’ DIFFERENTIAL RESPONSES TO A 
TUNING-FORK 
By F. L. Wells 
Harvard Medical School 
Patent factors in this behavior situation are, species and 
(developmental) age of the spider, position of the spider 
with reference to the nest, position of fork with reference 
to spider. Probably significant, but in the present circum- 
stances less readily observed factors include general ten- 
sional state of spider (as nutritional), conditions of temper- 
ature and illumination (season, night and day; present ob- 
servations mostly of daytime behavior), individual and sex 
differences. 
Present reference is to females half grown or more, unless 
otherwise specified. Species observed include mainly the 
common: Epeira insularis (30), 1 E. trifolium (15), E. 
domiciliorum (8), E. stellata (6), E. cavatica (40), Argiope 
aurantia (40), A. trifasciata (15). Cavatica was observed 
in northern New Hampshire, others mainly in eastern Mas- 
sachusetts. The earliest was of a young A. aurantia (7-7- 
35) ; the last of an old A. trifasciata (11-9-35). The fork 
was an ordinary Hartmann, designated C, 128. Normally 
it was sounded by striking smartly against the examiner’s 
knee or forearm. To control-observations with the fork 
silent, all spiders compared were, with the rarest exceptions, 
inert (Peckham, p. 391, also Peters, ’31, p. 698; Grunbaum, 
pp. 288-290). Neither did the retreat-dwellers respond to 
illumination by pocket flashlight, incidental to observation 
and photography at night. All observations were in the 
field, with minimal disturbance of spider’s domestic econ- 
omy. 
The patterns of behavior distinguished, and the circum- 
1 N‘umerals are approximate number of individuals observed; some 
on one occasion only, others repeatedly, and over several weeks. Es- 
sential help in taxonomy and nomenclature is received from Professor 
Nathan Banks and Miss E. B. Bryant. 
