PARTHENOGENESIS. 3! 



brood ; but this, instead of being composed entirely of similar 

 individuals, is made up of males and females. Sexual union 

 now takes place, and ova are produced and fecundated in the 

 ordinary manner. 



The bodies from which the young of the viviparous Aphides 

 are produced are variously regarded as internal buds, as "pseud- 

 ova " (i.e. as bodies intermediate between buds and ova), and 

 as true ova. 



Without entering into details, it is obvious that there is only 

 one explanation of these phenomena which will justify us in 

 regarding the case of the viviparous Aphides as one of true 

 parthenogenesis, as above defined. If, namely, the spring 

 broods are true females, and the bodies which they produce in 

 their interior are true ova, then the case is one of genuine par- 

 thenogenesis, for there are certainly no males. The case might 

 still be called one of parthenogenesis, even though the bodies 

 from which these broods are produced be regarded as internal 

 buds, or as "pseudova ;" for a true ovum is essentially a bud. 

 If, however, Balbiani be right, and the viviparous Aphides are 

 really hermaphrodite, then, of course, the phenomena are of a 

 much less abnormal character. 



In the second case of alleged parthenogenesis which we are 

 about to examine namely, in the honey-bee the phenomena 

 which have been described cannot be said to be wholly free 

 from doubt. A hive of bees consists of three classes of indivi- 

 duals T. A "queen," or fertile female; 2. The "workers," which 

 form the bulk of the community, and are really undeveloped 

 or sterile females ; and, 3. The " drones," or males, which are 

 only produced at certain times of the year. We have here 

 three distinct sets of beings, all of which proceed from a single 

 fertile individual, and the question arises, In what manner are 

 the differences between these produced ? At a certain period 

 of the year the queen leaves the hive, accompanied by the 

 drones (or males), and takes what is known as her " nuptial 

 flight " through the air. In this flight she is impregnated by 

 the males, and it is immaterial whether this act occurs once in 

 the life of the queen, or several times, as asserted by some. 

 Be this as it may, the queen, in virtue of this single impregna- 

 tion, is enabled to produce fresh individuals for a lengthened 

 period,, the semen of the males being stored up in a receptacle 

 which communicates by a tube with the oviduct, from which it 

 can be shut off at will. The ova which are to produce workers 

 (undeveloped females) and queens (fertile females) are fertil- 

 ised on their passage through the oviduct, the semen being 

 allowed to escape into the oviduct for this purpose. The sub- 



