SEX CONDITIONS 



external genitalia. Their ocelli are large re- 

 sembling those of normal males. Their normal 

 male instincts indicate that the brain is struc- 

 turally as in .the male, since mating reactions 

 in Habrobracon are determined by the brain. 

 Sclerotization of the abdomen is progressively 

 heavier anteriorly, approximating the condition 

 found in the female. Antennae of normal males 

 have about twenty-one segments in the f lagel lum, 

 those of females usually not more than fourteen. 

 In gynoid males the segments are reduced in num- 

 ber to that of the female, although they are not 

 quite as short and thick. Superficially a gyn- 

 oid male suggests a sex-mosaic or gynander with 

 female head and male abdomen. Certain struc- 

 tures intergrade , the body is approximately sym- 

 metrical with all parts presumably of the same 

 genetic constitution, and the type is perpetu- 

 ated as a pure-breeding form. 



Nine intersexual females have recently oc- 

 curred among the offspring of a single female. 

 Superficially these appear to be the reverse of 

 the gynoid males, being more masculine anterior- 

 ly and more feminine posteriorly. The heads are 

 characteristically male having large ocelli and 

 long antennae, the segments ranging from eight- 

 een to twenty-one v/ith tv/enty as the mode. 

 Tests made on five of the nine showed indiffer- 

 ence to caterpillars and vigorous attempts to 

 mate with females, indicating the brain to be 

 structurally male. Abdominal sclerotization is 

 male-like anteriorly. The first and second ter- 

 gites are thin and the anterior sternal thick- 

 enings small. Sclerotization is progressively 

 heavier posteriorly and sternal thickenings be- 

 come elongate, approximating the condition of 



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