Live-Stock Genetics 31 



particularly abundant in plumage pat- "The development of dairy heifers on 



tern. The spangled pattern of the different planes of nutrition, which has 



Silver Spangled Hamburg, for instance, been under investigation for the past 



is found to be sex-linked but, curiously seven years, has resulted in some 



enough, it is not transmitted as a unit interesting facts. The results indicate 



for the entire body, the tail seeming to that the method of feeding can influence 



follow a scheme of distribution of its the size, age of maturity and conforma- 



own; for in all reciprocal crosses, the tion of the dairy cow to some extent, 



tails of the Fi birds are solid black. A The milk secreting function, however, 



correlation between the hen feathering does not seem to be influenced to anv 



characteristic of male Sebright bantams, marked degree, if at all, by any ordinary 



and diminished fertility, is being sought variation in treatment. The milking 



by a series of bantam crosses. function is inherited and cannot be 



Heredity scores another victory in its influenced to any great extent by the 



popular contest with environment, as ration the animal receives when young." 

 the result of nutrition tests on cows. 



Eugenics Congress Postponed 



The executive committee of the Second International Eugenics Congress has 

 sent out the following notice : 



"On account of the situation in Europe and America created by the Great War, 

 the Executive Committee for the Second Eugenics Congress has regretfully decided 

 that it will be impossible to hold the proposed Congress in September, 1915. The 

 existing organization will be maintained, pending the reestablishment of settled 

 conditions, when the Committee will determine upon a new date. 



"The Executive Committee asks for the continued interest of those who have 

 consented to serve as members of the several committees and as officers of the 

 proposed Congress." 



The Determination of Sex 



Leonard Doncaster of Cambridge University contributes to Nature (October 1 , 

 1914) a note on his breeding experiments with the gall-fly. It is well known that 

 many Cynipid gall-flies have two generations in the year, one generation of par- 

 thenogenetic females and a second generation of males and sexual females. He has 

 previously shown that any individual parthenogenetic female has either only male 

 or only female offspring, and that the eggs of the male-producers undergo maturation 

 of a different type from those of the female-producers. He suggested the possibility 

 that the difference depended on the existence of two kinds of spermatozoa, but now 

 finds this a mistake and decides that the "difference between the male-producing 

 and female-producing females is derived from the sexual female parent. ' ' This type 

 of sex-determination has not previously been known in the Hymenoptera, but the 

 examination of over 9,000 flies bred make the experimenter certain "that nearly, if 

 not quite, all the grandchildren of any sexual female are of one sex, and that of the 

 sexual females, those which have male or female grandchildren are about equally 

 numerous." 



