ON PARTHENOGENESIS IN THE HYMENOPTERA. 201 



regarded as instances of retrograde development. 

 That many species have lost their males is very 

 evident. That, in getting rid of the males, they 

 have lost in bodily vigour, in so far as they have 

 become inert, sluggish, and, in fact, mere reproductive 

 machines, might readily be shown if time permitted. 



