144 HARRY FEDERLEY 
diesem Einfluss gespürt werden. In unserem Falle ware ich geneigt 
das Zytoplasma als das Milieu zu betrachten, in dem die Entwicklung 
der Chromosomen mit ihren Genen stattfindet. Für die Vererbung 
ist das Zytoplasma hier ohne Bedeutung. Inwiefern das Zytoplasma 
während seiner Bildung unter der Oogenese dagegen umgekehrt von 
den Chromosomen beeinflusst wird, ist eine andere Frage, die ich hier 
nicht diskutieren kann. | 
SUMMARY. 
The reciprocal bastards between the Linnean species Pygaera 
curtula and P. anachoreta show some interesting genetical points with 
regard to the coloration of the larvae. The dark pigment of the 
anachoreta-larva (Fig. 1) is dominant to the light pigment of curtula 
(Fig. 2). All larvae from the cross curt.? X anach. 4 resemble 
anachoreta on the whole. In the reciprocal bastard anach. © X curt. d, 
however, all 4-larvae resemble the mother anachoreta (Fig. 3) while 
the Q-larvae all resemble the father curtula (Fig. 4, cp. also Fig. 9). 
A typical case of criss-cross-inheritance in species crossing is thus 
seen to be at hand. 
It is not possible to raise any F,-generation of the latter cross as 
the development of the F,-male runs faster than that of the F,-female. 
Furthermore, the eggs of the latter do not seem to be vital. It is 
impossible, indeed, to carry out an analysis in the Mendelian sense as 
the normal course of the spermatogenesis shows great disturbances. 
The foreign chromosomes introduced in the bastard do not con- 
jugate but place themselves all side by side in the maturation-spindle 
and divide equationally not reductionally. Segregation fails and the 
spermatozoa contain a complete set of anachoreta- and curtula- 
chromosomes. 
The results of the reciprocal and the F, 4 X P,Q crosses might be 
understood if the assumptions are made (1) that the X-chromosomes 
show the same behaviour as the autosomes (2) that the larval pigment 
genes of anachoreta are localized in the X-chromosomes, (3) and that 
the Pygaera-species are homogametic (XX) in the male sex and hetero- 
gametic (XY) in the female sex in conformity to all other investigated 
cases in Lepidoptera. ; 
The F,-Z from the cross anach. 2 X curt. d crossed with an 
anachoreta 9 or a curtula ® gives in both cases only laryae which 
