Teacher's Leaflet. 



771 



branches of young hemlocks the fihiiy dome webs. They are about as 

 large as a small bowl and usually so delicate that they cannot be seen 

 unless the sun shines upon them, and then they are likely to be ex- 

 quisitely irridescent under the sun's rays. Such a dome may be studied 

 by a class or by the pupils individually. 



Observations by the Pupils. — (i). Where did you discover the filmy 

 dome ? 



(2). What is the size of the dome? 



(3). Does it open above or below? 



(4). How is it held in place? 



(5). Are there many crisscrossed threads extending above the dome? 

 If so, what do you think they are for? 



(6). Where does the spider stay? 



(7). Is the spider large and heavy or small and delicate? 



(8). What does the spider do if anything falls upon its web? 



(9). Throw a bit of a stick or leaf upon a filmy dome web and note 

 what becomes of it. 



Facts for the Teacher. — The dome is usually about the size of an ordinary bowl 

 and is suspended with the opening on the lower side. It is held in place by many 

 guy lines which attach it to surrounding objects. Above a filmy dome are always 

 stretched vnzuy crisscrossed threads for some distance up. These are for the 

 purpose of hindering the flight of insects so that they will fall into the web. The 

 little spider which is always stationed just below the center of the dome rushes to 

 its prey from the lower side, pulls it through the meshes of the web and feeds upon 

 it. But any remains of the insect or pieces of sticks or leaves which may drop 

 upon the web it carefully cuts out and drops to the ground, mending the hole very 

 neatly. 



Lesson XXII. 



BALLOONING SPIDERS. 



Purpose. — To observe how spiders travel and how the species are 

 distributed. 



Material. — These observations should be made out of doors during 

 some warm sunny day in October. 



Observations for the Pupil. — (i). Look across the grass some warm 

 sunny morning or evening of early fall and note the threads of spider silk 

 gleaming everywhere — not regular webs, but single threads spun from 

 grass stalk to grass stalk, or from one object to another, until the ground 

 seems glistening with silk threads. 



