Mollusks. Adapted for Grades 4A and 5A: 



Containing- shells of about twenty-five mollusks, including 

 specimens of the oyster, clam and chambered 

 nautilus 



Crabs. Adapted for Grade 5A: 



Containing relatives of the common blue crabs 



Starfishes and Worms. Adapted for Grades 4A and 5A: 



Containing typical species of the two groups 



Sponges and Corals. Adapted for Grades 4A and 5A: 



Containing about fifteen species of corals and their relatives 



Minerals and Rocks. Adapted for Grades 3B and 4A: 



Containing twenty specimens of minerals and building 

 stones 



Native Woods. Adapted for Grades 2A and 5B: 



Containing' elm, hickory, maple, white birch, ailanthus, 

 sweet-gum, sour-gum, chestnut, sycamore. Speci- 

 mens show cross, longitudinal and oblique sections 

 of the wood, characteristic bark, annual rings, etc. 



PUBLIC HEALTH FOLIOS 



Spread and Prevention of Communicable Disease: 



Containing fifteen photographic charts illustrating how 

 diseases are commonly spread and how they may be 

 prevented 



Insects and Disease: 



Containing twelve photographic charts illustrating' the life- 

 histories of some common household insects, which 

 carry disease. Conditions favorable for the breeding - of 

 these insects are also shown, as well as methods of 

 extermination 



Bacteria and Their Work in the World: 



Containing eight photographic charts illustrating beneficial 

 and harmful bacteria and their work 



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