80 HANDBOOK OF NATURE STUDY 



a great nuisance, because they fall into everything, soil our 

 houses and furniture, trouble us at table, and disturb us in 

 other ways. If barns and barnyards were kept clean, so 

 that flies could not find so many breeding places, and if no 

 refuse were thrown out near our homes, they would not be, 

 nor become, so numerous. Can flies see well ? Do you 

 think they can smell ? How would you prove it ? What 

 remedies do you know against flies ? Which would be the 

 most thorough remedy ? 



The different kinds of blowflies are larger than the house 

 fly, and are known by their loud buzzing. They deposit 

 their eggs on meat and dead animals. If a fish is placed in 

 the sun, the openings under the gills are filled with eggs in 

 a few hours ; so quick are the flies to find food for them- 

 selves and their maggots. 



NOTE. As the eggs and maggots of flies are revolting objects to 

 most children, it is not advisable to show them in class. 



37. The Spider. 



MATERIAL : An orb weaver, a cobweb weaver, and a funnel-web 

 weaver, each by itself in a rather large bottle. Place a few straws or 

 small sticks in the bottles, and collect the spiders a few days before 

 you use them. A few cocoons or balls with eggs. Some young spiders 

 recently hatched, if you can find any. An orb, enlarged, drawn on 

 the blackboard. In the following lesson the web and habits of the 

 common orb weaver, Epeira vulgaris, are described. Take any orb 

 weaver you happen to collect and describe its color and markings as 

 you find them. The males of many spiders are much smaller than the 

 females. Before this lesson the children should observe the three kinds 

 of spiders mentioned, and their habits. 



Spiders are not so numerous about our houses as the flies 

 which we studied in our last lesson, but if you collected all 

 the different kinds of spiders you could find, you would be 

 surprised to learn that there are perhaps as many different 

 kinds of spiders as there are different kinds of flies. To 

 most of us spiders do not seem pretty animals, like butter- 



