MAY 1 ]899 



MEMOIRS 



OF THE 



BOSTON SOCIETY OF NATURAL HISTORY 



VOLUME 5, NUMBER 5. 



THE DEVELOPMENT, STRUCTURE, AND AFFINITIES OF THE GENUS 



EQUISETUM. 



By EDWARD C. JEFFREY, 



BOSTON: 



published by the society. 

 '-■'^ April, 1899. 



