598 PHOTOPERIODISM IN INVERTEBRATES 



physiological level. Nevertheless, the investigator is offered many 

 practical advantages. The possibility of obtaining abundant and 

 uniform material is one. The ease with which many insects are reared 

 and their high intrinsic rate of development are others. These con- 

 siderations may suggest that this field will continue to attract the 

 attention of the student of photoperiodism. 



REFERENCES 



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