232 PROCEEDINGS OF THE ACADEMY OF [1880 



My investigations have been made only on the Lemna .minor ^ 

 but there is no reason to doubt that in the development of the 

 "whole family of Lemnacese (analogous to our species) we have an 

 interesting instance of parthenogenesis, there being seeds (pro- 

 duced in autumn by a sexual process) from which, during the 

 course of summer, generation after generation is propagated with- 

 out any further fertilization. 



