604 RICHARD GOLDSCHMIDT 



In former papers we have also reported that ia certain crosses 

 where the factorial 'potencies' are extremely abnormal, nothing 

 but males are produced, the would-be females being completely 

 transformed into males. The theory proposed in this paper 

 would require that in this case the turning-point is so early that, 

 practically from the beginning of differentiation, development is 

 male. We have recently tested the behavior of the sex-glands 

 by killing complete cultures (all the caterpillars descended from 

 one egg-batch, with practically no mortality) of such crosses in 

 the five stages of the caterpillar. All these individuals in the 

 different stages contained macroscopically and microscopically 

 normal testes. There is only one point left unsettled. If the 

 'turning-point' occurs when the ovarial tubules are already well 

 developed, the latter will cease to develop, and no more eggs 

 will ripen. This is exactly what happens. But, if the turning- 

 point does not occur at too late a stage, say in high-grade inter- 

 sexuals, the end-filament of the ovarial tubules may possibly 

 have time to dedifferentiate and to form testis tissue from the 

 Ureier. An infectious disease in our cultures has prevented 

 our testing this point, which was overlooked in former years. 

 We hope next year to fill the gap. 



To complete the evidence for the sex-glands we must see 

 whether the theory holds good for male intersexuality. This 

 has proved to be the case, at least as far as intersexual males 

 have been bred (the very last steps could not be obtained). 

 The ovary is a paired organ; the testis is paired in the cater- 

 pillar, the two parts becoming fused during pupation. In some- 

 what progressed intersexual males the testis is paired. Nor- 

 mally the testis always contains a sufficient supply of primordial 

 sex-cells. These would be expected — if really undifferentiated — 

 to grow into ova from the moment when the action of the gynase 

 starts. As a matter of fact intersexual males contain in their 

 testes nests of young ova. Thus, as far as our work has gone, 

 the facts prove to be in perfect harmony with the theory. 



