nature; study lessons. 237 



the eaves of buildings. These make a very strong and 

 tough covering of paper for the protection of the colony 

 from the weather. The social wasps, whether they make 

 a single comb or a paper-covered nest, belong to the family 

 Vespidse. 



Of the solitary wasps, there are a great many kinds, 

 and each kind has its own habits of life. There are as 

 many as seven families of these " digger wasps," as they 

 are called, those which children in New England will find 

 most common, provision their nests with spiders. They 

 belong to the family Pompilidae. In the west and south- 

 west, a kind that stores its nest with grasshoppers is abun- 

 dant and belongs to the family Laridae. 



All children in the country know the " mud-daubers," 

 that make nests of mud, which they fasten to the under 

 side of stones and in the attics of houses. Most of them 

 stock these mud nests with spiders, and many a child has 

 wondered how the spiders got there. These mud wasps 

 belong to the family Sphecidye. 



The order Hymenoptera is a very large one, and it is 

 impossible in a nature study lesson to more than mention 

 a few of the families, leaving many others to another les- 

 son or until the children have learned more about classifi- 

 cation. 



Until recently pitchblende has been the only source of 

 radium, but now carnolite, a mineral found in Utah, is 

 found to be a commercial source of the rare element. For 

 some reason it does not seem to possess so much radio-ac- 

 tivity as that obtained from pitchblende, but carnolite is 

 henceforth to be regarded as one of the sources of radium. 



Here are trees, and bright green grass, and orchards full 

 of contentment, and a man may scarce espy the brook, al- 

 though he hears it everywhere. — Lonia Doone, 



