E. A. Cockayne 121 



He gives the following formulae fur the two sexes: 

 The male = FFMMGGAA or more correctly (FG){FG)(iMA){MA). 

 The female = FFMmGGAa or {FG){FG){M A){iaa). 

 The male gametes arc all of one kind {FG){MA) and the female of 

 two kinds {FG){ma) and {FG){MA). 



In Lymantria var. japonica he considers that the relationship 

 between /' and M and between G and A is the same, but that each 

 factor is of much gi-eater potency than in L. dispar. For A in japanica 

 he gives a value of 120 and for G a value of 80. The factors for japonica 

 he writes in thick capitals (e.g. F in place of F, &c.). 



According to this scheme the individuals constituted GGA(/, QGAa, 

 GGAa, GGAa would be normal females, and those constituted GfrAa, 

 GGAa would be gynandromorphous females. 



Gynandromorphous males would be constituted GG.il..4. Gynandro- 

 morphous females were produced in the broods, where such combinations 

 of factors were possible, and in the expected numbers. Gynandro- 

 morphous males were not produced in one brood, in which they were 

 expected, but in another they appeared in the expected proportion of 

 one to every seven normal males. 



In one brood no females were produced, all were males (408) or males 

 with small specks of white sprinkled all over them (71) (weibchen- 

 mannchen). To explain their appearance he assumes that the potency 

 of the sex factors F and M can be lowered by inbreeding. He regards 

 them as the product of a dispar with the constitution FFMm, F and M 

 being of unusually low potency, crossed with a japonica of the constitu- 

 tion FFMM. The weibchen-miinnchen were thus constituted i^FMw 

 and in tliein the great relative potency of the male factor obliterated 

 the female almost completely. 



Another cross between individuals constituted FFMm and VFMM 

 gave half normal females, FFifrii and FFMin, and half weibchen- 

 mannchen, FFMta and FFMm. Those with formula FFMm are 

 unrecognisable from normal males in external appearance. Hence the 

 apparent result of this cross is always 2 females : 1 weibchen-manuchen : 

 5 males. 



Even if the explanation of their gyoiandromorphous families given 

 by these authors is correct and we accept the view that they are due to 

 differences of potency in the factors for sex and secondary sexual 

 characters and that inheritance of these follows the simple Mendelian 

 laws, we cannot extend the explanation to cover all instances of 



