1936] Orbweavers’ Responses to a Tuning-Fork 13 
Peters ’33, also Griinbaum, p. 292), if sufficiently vibrating 
when spider reached it. Seizing movements normally 
ceased as vibration of fork subsided ; might or might not be 
renewed upon reactivation of fork (cf. Peters as above; 
also Rabaud pp. 37, 41). 
The above tuning-fork responses are much modified and 
decreased when the spider has a support other than the web 
(not especially in Grimbaumfs observations, p. 296), or 
when the spider is not at rest. In the individuals compared 
(mostly car utica, aurantia and Uloborus) there was little 
difference in the responses observed to a comparison fork of 
designated 256 rate (cf. Barrows, p. 321; Peckham, p. 391; 
Griinbaum, p. 295). To the much greater volume of sound 
from a dry-cell operated telegraph buzzer similarly pre- 
sented, practically all individuals observed were inert 
(Peckham, p. 390, contrary to Savory, pp. 90-91; cf. also 
Peters, ’31, p. 705). 
References 
Barrows, W. M. The reactions of an orb-weaving spider, Epeira 
sclopetaria Clerck, to rhythmic vibrations of its web. Biol. Bull., 
1915, 29, 316-332. 
Boys, C. V. The influence of a tuning-fork on the garden spider. 
Nature, 1881, 23, 149-150. 
Griinbaum, A. A. Ueber das Verhalten der Spinne ( Epeira diadema- 
ta) besonders gegeniiber Vibrator ischen Reizen. Psychol. For- 
schung, 1927, 9, 275-299. 
Peckham, J. W. and Peckham, E. G. Some observations on the mental 
powers of spiders. J . Morphology, 1887, 1, 383-419. 
Peters, H. Die Fanghandlung der Kreuzspinne. Experimentelle 
Analysen des Verhaltens. Zsch. f. vergl. Physiol., 1931, 15, 693- 
749. 
Peters, H. Weitere Untersuchung iiber die Fanghandlung der Kreuz- 
spinne (Epeira diademata Cl.) Zsch. f. vergl. Physiol., 1933, 19, 
47-67. 
Rabaud, E. Recherches experimentales sur le comportement de di- 
verses Araignees. Annee Psychol., 1922, 22, 21-57. 
Savory, T. H. The biology of spiders. New York: Macmillan, 1928, 
pp. xx + 376. 
