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Psyche 
[December 
at the hub, but merely attached by the transport thread, on arrival. 
Thus the transport thread functions as an attachment thread. 
Wrapped prey that are carried in the jaws do not have a transport 
thread and are wrapped again at the hub. 
2. Post immobilization wrapping at the capture site reinforces the 
immobilization achieved by the poisoning bite, facilitates the removal 
of strongly adhering prey from the web, and enables the spider to 
safely store prey in situ. In addition, it may facilitate the transpor- 
tation of large or heavy prey. The behavior of Nephila provides 
evidence for the separate functions associated with prey removal 
and transportation. Thus prey which Nephila can remove by pulling 
are not wrapped in the web but may be wrapped before being carried 
to the hub. Argiope only pulls very small prey from the web, and 
cuts out all other prey after wrapping has produced a compact prey 
package. The occurrence of post immobilization wrapping during 
transportation is a further example of wrapping functioning to facili- 
tate transportation. 
3. Immobilization wrapping effectively immobilizes prey, and com- 
pared with immobilization biting, allows the spider to attack without 
bringing its more vital parts into direct contact with the prey. It 
may thus be less dangerous than immobilization biting. Furthermore 
it is economical of time and this may be a very important factor. 
As far as we are aware there are no araneids that do not bite 
after immobilization wrapping. Uloborids, on the other hand, rely 
exclusively on wrapping for prey immobilization (Eberhard 1967). 
The short bite of araneids, or at least those that we have studied, 
contains some poison since prey removed from the prey package after 
the short bite eventually become completely quiescent. It therefore 
seems probable that the short bite supplements the effect of the 
immobilization wrapping. Uloborids are all quite small spiders and 
it seems possible that total reliance on immobilization wrapping might 
be less efficient in the case of the araneids (which may rely heavily 
on stronger and more active prey). 
The performance of Argiope argentata and Nephila 
clavipes confronted with a rapid succession of small prey 
In the above discussion of the functional aspects of wrapping be- 
havior we have stressed the possibility that economy of time spent 
in prey capture sequences may be obtained by leaving prey in situ 
after it is wrapped. We have also pointed out that this is possible 
as a consequence of both immobilization wrapping and post immobili- 
zation wrapping at the capture site. Economy in time spent away 
