196 ARTHROPODA 



6. Find the position of the anus. The terminal spine is 

 provided with a poison gland and serves as a sting. In the 

 living animal, the postabdomen is habitually carried over the 

 back. 



Make a drawing of the under side of a specimen. 



EPEIRA (Round-web Spider) 



Examine the webs of different species of spiders and see 

 how they are constructed. Do all of the webs have places 

 for the concealment of the owners? Do all spiders seem to 

 construct definite webs for the capture of insects? How do 

 spiders entangle insects in their webs? Do different kinds 

 use different methods? What parts of insects are eaten? 



By destroying webs that are occupied by spiders that are 

 in convenient places for observation, the construction of new 

 webs may be observed. Notice how the framework of a round 

 web is laid and then how the threads are attached to the 

 framework. Are any of the legs used in handling the thread? 

 Are spiders equally active at all times of the day? 



Spiders' webs may frequently be seen floating in the air, 

 especially in the late summer or autumn. By watching 

 spiders that are on fences and bushes the formation of these 

 threads may be observed. Watch such a spider and see if you 

 can determine the use to which the thread is put. 



Capture a spider and watch it descend by a thread. 

 Where is the thread formed? Does the spider hold to it with 

 its legs? Keep taking the thread up so that the spider can- 

 not reach the ground, and see if there is a limit to the 

 amount that can be formed. When the spider starts to climb 

 the thread see how this is done, and whether the thread is 

 taken up as the animal climbs or is allowed to float free. 



Find where spiders lay their eggs. Some carry them. If 

 you can find a specimen with an egg sac, see how it is carried 

 and whether it will drop its eggs when frightened. Remove 

 the egg sac and see if the spider will accept it again. Open 



