SECONDARY SEXUAL CHARACTERS OF CRAYFISHES. 2$l 



similarity from which it could be inferred that they might have 

 been members of the same brood. The evidence from Lake 

 Delavan for the inheritance of the intersex condition lies in the 

 fact that at least three generations of crayfishes were represented 

 in the specimens secured. If the peculiar condition were being 

 transmitted it should be expected that the same proportion of 

 intersexes would obtain in specimens representing different ages. 

 This was found to be the case. Admitting that constant but 

 peculiar environmental conditions might be a po>-il>le cause it is 

 strongly -u-pe< ted that the cause for the intersex condition lic> in 

 some change in the genetic constitution, possibly in the chromo- 

 some complex and that the condition is being inherited. It is 

 propo.-el to ti -t this inference by collecting intcr-e\ leinales 

 which arc bearing eggs and to rear the eggs to maturity or to such 

 a time .1- it \\ill be possible to determine- \\ hether or not the young 

 possrss the peculiarities of the mother. 



