306 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1957 



oo 



O/A 





o 



© 



monolete scar 



wings 



furrows 



> no aperture 



no aperture 



I pore 



no aperture 



3 to many pores 

 3 to many 

 f u r rows 



3 to many 

 f u rrows 

 ond pores 



ferns 

 and 

 fern allies 



gymnosper- 

 -mous plants 



monocotyledo 

 -nous plants 



dicotyledonous 

 plants 



Figure 1. — Some common pollen and spore forms. 



