180 ARTHROPODA. 



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 entan- 

 gle 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 famework. 

 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 deter- 

 mine 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 cannot 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 Of 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 several 

 egg-sacs and see if the eggs all appear to be in the same stage 

 of development. 



Study the movements of the animal and see how many oi 

 the appendages are used in locomotion. Are any of the appen- 

 dages used sometimes for locomotion and sometimes for feel- 

 ing? 



Examine the external structure of Epeira. 



