560 THE ENTOMOLOGIST. 



The curious facts, as now understood, in the economy of 

 the common bee-hive, seem at first to militate against the 

 conclusion that food has no influence on the sex of larvae, but 

 in reality they do not, though they indicate that the sex may 

 be altered or determined after partial or imperfect conception 

 has already taken place. All eggs not directly impregnated 

 produce drones or males {not females, as " A. S. P.," by a 

 singular lapse of thought, has stated on p. 177 of the March 

 number of the ' Naturalist'), while those which are impreg- 

 nated at the will of the mother produce females either partly 

 or fully developed, i.e., workers, or queens. The rule with 

 animals is that the eggs perish unless vitalized by the direct 

 influence of the male spermatozoa. Nevertheless, parthenoge- 

 nesis in many of the lower forms of animal life, and especially 

 in insects, is an admitted fact. And what does it imply ? To 

 my mind it implies that in exceptional cases the male element 

 is sufficiently potent to vitalize the eggs in the second gene- 

 ration, or that it may endure until succeeding generafions ; 

 that, in short, to use Owen's words, " the spermatic virtue of 

 the ancestral coitus" may influence the descendants. Von 

 Siebold does not accept this explanation, but there are many 

 facts which indicate that it is a true one, and the male element 

 becomes exhausted in time, and is needed sooner or later for 

 the continuance of the species. 



Parthenogenesis has repeatedly occurred in species which 

 normally cannot multiply without direct sexual intercourse, e.<7., 

 in Bombyx mori. Sphinx ligustri, &c., while in a great number 

 of others the embryo, in eggs not directly fecundated, develops 

 up to different stages. What in some species is the exception 

 becomes the rule with others, of which the hive-bee is an 

 example. The male element may be said to possess all 

 degrees of potency in its influence on the reproductive 

 function of its immediate issue, as the embryo in eggs not 

 directly fecundated attains all degrees of development before 

 death. In cases of parthenogenesis it is potent enough, 

 vital enough, to cause full development of the offspring for 

 one or more generations, though, in the majority of instances, 

 and especially where this mode of reproduction does not 

 occur as a rule, this offs))ring is most frequently male. 

 Finally, it may be so potent, as in what is termed thelotoky, 

 that females instead of males are produced. 



