75i 



THE AMERICAN NATURALIST [Vol. XLVIII 



many original types none were distinguishable. Finally 

 a genuine new "type" appeared, with both wings alike 

 and definitely "notched" (Fig. 13, p. 730). This female 

 which was at sight named Perfect Notched, was mated 

 to Wild. Her ancestry was as follows : 



The grandmother came from pure Beaded stock, and 

 the grandfather from Wild stock. Their offspring con- 

 sisted of 13 Beaded and 69 normal flies. 



A Beaded female of this generation was mated to a 

 normal brother and gave 100 Beaded offspring, male and 

 female, and one "perfect notched" female. 



This female and her descendants behaved in a very 

 different manner, genetically, than the Beaded stock 

 from which she arose. 



She was mated to a Wild male and gave 62 Beaded off- 

 spring and 112 normal offspring. Of the Beadeds, 50 

 were notched in a way resembling the parent and of the 

 50, 49 were females. Several other peculiar wing types 

 appeared among the remaining 12 Beaded flies of this 

 generation, but did not breed true and were later dis- 

 carded. 



The notched male gave ordinary Beaded and normal 

 offspring and never gave in either the first or later gen- 

 erations any "notched" offspring. He was probably an 

 extreme variant of a common Beaded type (Fig. 4). 



Of the normal offspring of the Perfect Notched female 

 four pairs were made up. Seven hundred and forty-nine 

 normal sons and daughters appeared, and no notched. 



Of the notched daughters of the perfect notched female, 

 two were mated to normal brothers and two to Wild 

 males. Their progeny was : 



By wild males 56 47 46 



Six of the notched females of this generation were 

 mated to normal brothers and gave 



At this time, June, it was necessary to leave New York. 

 In traveling, the Perfect Notched stock was lost. Enough 



