I 



PATTERSON] A STUDY OF SPIDERS 271 



autumn or early winter may help to solve the problem. Look 

 under loose pieces of bark also under logs and boards for webs 

 in which spiders are enclosed for their winter sleep. Have the 

 children watch house-spiders that remain in their webs in cellars 

 or attics to determine whether they remain alive during the winter 

 months. 



Additional Facts 



The study of spiders conducted as suggested above, means that 

 the children are investigating, observing, seeing things as they are, 

 and drawing conclusions from what they see. They are gaining 

 knowledge at first hand and are having a good time while they are 

 doing it. There are, however, some facts of interest concertiing 

 spiders that the children will not be able to discover for them- 

 selves. These may be told by the teacher. In my own work I 

 find that most of the facts indicated below, have been given in 

 response to questions on the part of the pupils. 



The Silk and the Spinnerets — The silk is secreted in liquid 

 form by glands in the back part of the abdomen. The spinnerets 

 consist of six blunt projections resembling finger tips, which are 

 located in the back part of the abdomen on the under side. Each 

 spinneret has a great number of small tube -like openings. When 

 the spider wishes to spin, she gently presses a spinneret against 

 some object and forces a small amount of liquid from the spin- 

 nerets. This sticks to the object. Then she moves her spin- 

 nerets in just the right way to draw the liquid from the tubes. 

 The instant it comes in contact with the air, it hardens into a 

 thread. The liquid pours out of all the small openings, but the 

 many threads unite to form one before they are dry. 



We have found that there are two kinds of silk. The sticky 

 kind is spun by using one set of spinnerets and the dry by the 

 use of another set. The spider uses the different kinds of silk as 

 she chooses. The claws on the hind legs are used to aid in man- 

 ipulating the thread. 



The Poison Fangs — Are spiders poisonous and where does the 

 poison come from — are famiHar questions. At the tip of each 

 mandible is a sharp spine-like claw. The children may be able 

 to see this in some of the larger spiders. This spine is called the 

 poison fang. In the head just above the mandibles arc small 

 glands which secrete a posionous juice. A small duet cxIcmkIs 

 from the gland to each poison fang. The spider uses the fang 



