390 GENERAL BIOLOGY 



Of group 3, diving beetles, water boatmen, back swim- 

 mers, water bugs, mosquito pupae, cranefly larvae, 

 frogs, snails, etc. 



Of group 4, Ranatra and rat-tailed maggot. 



Of group 5, Corethra, mosquito larvae, Daphnia, and a 

 number of other micro-crustaceans. 



Of group 6, damselfly, mayfly and some dragonfly 

 nymphs, amphipods, newly hatched amphibian 

 larvae, etc.) 



Of group 7, hydras, vorticellidae, bryozoans (especially 

 Plumatella), etc. 



Of group 8, crawfishes, dragonfly nymphs, Asellus, etc. 



Of group 9. Tubifex, dragonfly nymphs, small mussels, 

 nymphs of Ephemera, etc. 



The record. — Find and include in the table as representa- 

 tive an assemblage of forms as possible. Where many allied 

 forms of closely similar habit are found, use but one example. 



II. ADJUSTMENT IN MANNER OF LIFE, 



We select for study under this heading three subjects only: 

 i) Symbiosis: the adjustment in mode of life of two 



different organisms enabling them to live together in union 



with mutual advantage. 



2) Parasitism: adjustment in mode of life between two 

 different organisms for the benefit of the smaller and for the 

 detriment of the larger. 



3) Pollen production in flowering plants in relation to its 

 distribution; the adjustment of one special plant function in 

 relation to physical and animal environment. 



I . Symbiosis 



Lichens are the best as well as the commonest illustrations 

 of this phenomenon. Lichens may be gathered at any time 

 from the trunks of trees, from stones and fences, and from 



