1938] 
“Shuttling” in Argiope aurantia 
67 
involving fork-to-dorsum stimuli is but 50 against 129 of 
1935. The amount of observation in the 1936 studies is com- 
parable, being more intensive and controlled than previously. 
The following figures are with reference to time of year, 
tabulated in the same general manner as the 1935 data, by 
occasion, only one response reckoned per occasion ; shuttling 
if it occurred, otherwise the principal response that was 
made : 
7-11-36 
8-1-36 
9-5-36 
Dates 
to 
to 
to 
Occasions with fork- 
7-31-36 
8-15-36 
9-20-36 
to-dorsum stimulus 
28 
11 
11 
per cent shuttle 
57 
36 
9 
per cent spread 
7 
27 
45 
per cent reach 
11 
9 
18 
per cent seize 
14 
27 
18 
per cent others 
0 
0 
0 
per cent imperceptible .... 
11 
0 
9 
The psychology indicated differs somewhat from that of 
1935. More in detail ; on 7-11-36 four young aurantias were 
observed for the first time of any that year. In these indi- 
viduals and one other, the apparent order of somatic matura- 
tion was one day later, from least to most, nos. (3), (1), (5), 
(4), (2), To initial fork-to-dorsum stimulus, (1) and (4) 
shuttled at once; (2) reached and then shuttled; (3) reached 
slightly, then dropped to substratum. Response to sub- 
sequent (not necessarily in succession) fork-to-dorsum 
stimuli were : 
1 After spontaneous return in 2 minutes, reaching reactions, dimin- 
ishing to imperceptible (fork 128); spread to fork 256. 
2 Four shufflings with spontaneous returns, in about 10", 45", 4' and 
5' respectively; succeeding four shufflings preceded by reaches, 
but no extinction. 
3 After return to orb-centre in 5', seven shufflings from original 
position, with time of spontaneous return as follows: 30", 2', 1', 
15", 7", 10", 40". 
4 Four alternate shufflings and back, all to stimulation; on next 
stimulus, drop to substratum. 
On next observation, 7-12-36, 4 was unavailable, others reacted as 
follows: 
