Other Invertebrate-Anbval Study 



481 



10. How does the spider make fast an insect ? Does it bite the insect 

 before it envelops it in silk? Where does it carry the insect to feed upon 



it:^ 



1 1 . How does the spider manage to run about its web without becom- 

 ing entangled in the sticky thread ? How often does the orb- weaver make 

 a new web ? 



Haw an Orb-web is Made 



Spiders may be seen mak- 

 ing their webs in the early 

 morning or in the evening. 

 Find an orb-web with a spider 

 in attendance ; break the web 

 without frightening the spider 

 and see it replace it in the 

 early evening, or in the morn- 

 ing about daybreak. An orb- 

 weaver may be brought into 

 the house on its web, when the 

 web is on a branch, and placed 

 where it will not be disturbed, 

 and thus be watched at 

 leisure. 



Observations — i. How 

 does the spider manage to 

 place the supporting line be- 

 tween two points? 



2. How does it make the 

 framework for holding the 

 web in place? 



3. How does it make the first radius? 



4. How does it make the other radii and select the point which is 

 to be the center of the web? 



5. How does it keep the line which it is spinning 

 clear of the line it walks upon? 



6. After the radii are all made, are they fastened at 

 the center? 



7. How and where does the spider first begin to 

 spin a spiral ? Are the lines of this spiral close together 

 or far apart? For what is the first spiral used? 



8. Where does it begin to spin the permanent 

 spiral? Where does it walk when spinning it? By Thczif^Ziitistroifith- 

 the way it walks on the first spiral, do you think it is etiini^'hand at center 

 sticky and elastic? What does it do with the first of an orb-web. 

 spiral while the second one is being finished? 



9. If the center of the web has a zigzag ribbon of silk, when was it put 

 on? 



ID. How many minutes did it take the spider to comj)lete the web? 

 Supplementary reading — "Argiope of The Silver Shield," Insect Stories, 

 Kellogg. 



A partially completed orb-web. 



a, the temporary spiral stay line; b, the sticky 

 spiral line; c, the fragments of the tem- 

 porary spiral hanging to a radius. 

 Comstock's Manual. 



