192 FIRST LESSONS IN ZOOLOGY 



room. Some thoroughly interesting experiments may be 

 made with them. 



The make-up of the spider body. — Have a number of 

 common house-spiders (readily found in wood-sheds, 

 stables, attics, etc.), and of ground-spiders (to be found 

 under stones and boards) alive in glass jars. Put some 

 small live insects in the jars for food. Observe the be- 

 havior of the spiders. If they capture the insects note 

 what is done with them. Is there any difference in the 

 behavior of the two kinds of spiders.-" Do they spin silk 

 about their prey.'' If they spin silk about the prey do 

 they spin any more .'' Do they eat the whole body of the 

 captured insect.'' Where does the silk come from.' Take 

 out from the jar one of the house-spiders on the end of a 

 pencil. It will drop, not free, but attached to a delicate, 

 almost invisible, silken thread, which issues from the 

 posterior tip of the body (fig. 149). By quickly lifting the 

 pencil before the spider reaches the table or floor the 

 holding thread may be observed. 



Kill some of the larger individuals in a killing-bottle 

 (see p. 335) and carefully examine them. How many legs 

 has a spider.' A pair of short processes 

 which look, at first glance, like legs and 

 are situated in front of the first pair of 

 true legs, are feelers or palpi — not the 

 same kind of feelers as the antenna; of 

 insects, but feelers belonging to the 

 Fig. 150.— Tlic eyes mouth. Into how many principal parts 



.-iiiil jaws, showiiu' ..... 



fills :ui.l 1,111(4 (if a IS the bod\' divided.'' these parts have 



spi.lei. (After Jen- the same name as those of the cra\'fish 



kins anil keilnuL;.) ^ 



The spider body is really built on the 

 segmented plan (like the worms, crustaceans, ccntipeds, 

 and insects), but the segments have grown together so 

 that the lines or sutures between them are obsolete. To 

 which part of the body are the legs attached ? Are there 



