Basis of Sex Determination 221 



festations of maleness or femaleness, both in mor- 

 phological characters and instincts. Goldschmidt calls 

 this peculiar phenomenon intersexualism, and its 

 essential feature is that the various degrees of inter- 

 sexualism can be produced at will by the right 

 combination of races. 



Female intersexualism begins with animals which show 

 feathered antennas of medium size (feathered antennae 

 are a male character), but which are otherwise entirely 

 female in appearance except that they produce a smaller 

 number of eggs which are fertilized normally. In the next 

 stage patches of the brown male pigment appear on the 

 white female wings in steadily increasing quantity. The 

 instincts are still female, the males are attracted and 

 copulate. But the characteristic egg sponge laid by the 

 animal contains nothing but anal hairs in spite of the fact 

 that the abdomen is filled with ripe eggs. In the next stage 

 whole sections of the wings show male colouration, with 

 cuneiform female sectors between, the abdomen becomes 

 smaller, contains fewer ripe eggs, the instincts are only 

 slightly female, the males are attracted very little, and re- 

 production is impossible. In the next stage the male 

 pigment covers practically the whole wing, the abdomen 

 is almost male, but still contains ovaries with a few ripe 

 eggs, the instincts are intermediate between male and 

 female. Then follow very male-like animals which still 

 show in different organs their female origin and have rudi- 

 mentary ovaries. . . . The end of the series is formed by 

 males, which show in some minor characters, such as 

 the shape of wings, still some traces of their female origin. 



The series of the male intersexes starts with males show- 

 ing a few white female spots on their wings. These be- 

 come larger and larger, the amount of brown pigment 



