66 
Psyche 
[March 
shuttling, the venter is towards the fork, a quite different 
stimulus situation, having its own patterns of response. On 
these 18 occasions, shuttling was preceded by spreading in 
9 instances; by reaching in 5 instances, by seizing in one 
instance. In two instances the spider after shuttling, re- 
treated, and in another instance withdrew the abdomen 
(common response in the young trifasciata ) . The spread- 
ing, reaching and seizing here combine with the shuttling in 
reverse order of their aggressiveness, but this was not the 
case in 1936. 
Shuttling to other stimulus. In the 129 occasions of 
present reference, the stimulus is given by the fork approxi- 
mated to the spider's dorsum, at orb-centre. Other analogous 
stimuli, to perhaps six times this number, were also applied, 
including fork vibrating in other positions, and silent but 
oscillated. Shuttling was observed to stimuli other than 
vibrating fork-to-dorsum on 9 of these occasions. One of 
these shuttlings was to a vibrating fork touched to the 
periphery of the orb ; two were on fork-to-dorsum but spider 
not at orb-centre; two were on the approach of a fork 
silent but rapidly oscillated. One individual shuttled upon 
vibrating fork stimuli applied to dorsum, venter and orb 
periphery. When to venter, it is towards the fork; there 
was one other instance of this anomalous response. In one 
instance the shuttling occurred when the fork touched a leg ; 
in another, upon the examiner's mere approach. Fork-to- 
dorsum with aurantia not at orb-centre is a situation little 
observable, but the response to it is probably similar to that 
at orb-centre. 
1 936 Data 
During 1933, 1934 and 1935, A. aurantia was abundant in 
the area concerned. At the close of the 1935 season, eggsacs 
were found with exceptional readiness. In 1936, the earliest 
individuals were observed at a date comparable to 1935 
(about 3 weeks later than 1934), and in numbers compared 
well with the young of the two previous years ; but although 
search was carried on with similar care, a scant dozen indi- 
viduals were observed during this year, that were past the 
adolescent stage. (The Argiopes seemed more affected than 
other species ; trifasciata especially so. ) The total occasions 
