98 



SEX INHERITANCE 



genetic female producing many sons, according to 

 whether she has been fertiUzed soon after hatching 

 or not. The nature of the change in this female is 

 not known, but it is known that the small male- 

 producing eggs extrude two polar bodies, thus be- 



Fig. 33. — H.ydatiiia scnta. — A, the ordinar.y parthenogenetic female. 



B, sexual female, at time of hatching, when she is fertilized by the male. 



C, male. D, parthenogenetic female egg. E, parthenogenetic male egg. 

 F, fertilized resting egg. (After Whitney.) 



coming haploid. These males produce two kinds of 

 sperm, functional and non-functional; there are 

 just twice as many of the former as of the latter 

 (Whitney). In this respect the case appears similar 

 to that of the hornet, the male of which is haploid 



