Wilmarth, David Lincoln2013-04-092013-04-0919501950b14748484https://hdl.handle.net/2144/5417Text is accompanied by 30 colored slides. Thesis (Ed.M.)--Boston Universityen-USBased on investigation of the BU Libraries' staff, this work is free of known copyright restrictionsCertain biological principles illustrated by natural color slidesThesis/Dissertation