Spid 



ers 



Having reached the limit of her travels, a limit which 

 is determined by the discovery of a suitable object to 

 which the other end of the foundation line may be 

 attached, she stops and pulls the slack thread taut, then 

 fixes it by applying her spinnerets to the support. In 

 this manner she proceeds till all her foundation lines are 

 completed. Should they require further strengthening, she 

 repeats the process, spinning more silk the while. Not 

 till these lines are quite strong and taut is the rest of 

 the work put in hand. 



The construction of the radii or spokes of the web is 

 the spider's next care. She begins operations by fixing 

 a thread to the centre of the upper foundation line and 

 dropping with it to the lower line, where it is fixed. 

 From the centre of this line she runs spokes in all 

 directions to the bounding foundation lines. She works 

 apparently at haphazard, but in reality the spokes are 

 arranged so that the tension on the foundation lines is 

 fairly uniform. In the hub of the web the little worker 

 then spins a few irregular threads to afford a foothold 

 and, starting from this point, she spins a spiral line of 

 silk which she attaches to each of the spokes in turn. 

 Creeping from spoke to spoke, and working from centre 

 to circumference, the construction of this transient struc- 

 ture, which is merely a scaffold for future operations, is 

 but the work of a few moments. 



Now the most important part of the orb remains to be 

 laid down, the spiral of sticky threads upon which the 

 insects are caught. Beginning at the circumference, the 

 mother spider works towards the centre, stepping carefully 

 on the scaffold threads as she goes. As she spins her 

 sticky thread she affixes it carefully to each spoke in 

 turn ; having done so, she pulls at it with her foot and 

 then suddenly releases it. The reason for this strange 

 proceeding we shall learn presently. As she joins each 

 spoke with its neighbour by means of a sticky thread, 

 she bites away the connecting threads of the first-formed 



266 



