The Chromosomes of Euschistus variolarius, Euschistus ser\nas etc. 
501 
The results of oiir cross-breeding experiments demonstrate that this 
exclusivelj" male character can be inherited without the aid of the X cliro- 
mosome, and without the aid of the Y chromosome, and fiirther, they 
demonstrate that the factors deterniining the transmission of this ex- 
clusively male character cannot logically be confined in one or both inein- 
bers of any definite pair of the ordinary chromosomes. The facts, there- 
fore, challenge all those hypotheses that are based on the assumption 
that the factors deterniining the transmission of unit characters are car- 
ried and distributed by definite chromosomes. 
Recently Federley (T3) has drawn some important conclusions 
based on his observations as to the behavior of the chromosomes in the 
Fl hybrids obtained from Crossing Pygaera curtula, anachoreta etc., and 
he has offered these in explanation of some of the results of his cross- 
breeding experiments. He finds the inheritance of certain characters in 
the Fl hybrids quite as difficult to classify as we find the genital spot 
in the hybrids of Euschistus. He says : 
»Ich konnte nämlich keine unzweideutigen Beweise für eine alter- 
native Vererbung finden, aber gleichzeitig schien mir das Vorkommen 
der sogenannten konstanten intermediären Vererbung noch unwahr- 
scheinlicher . . . . « (pag. 5). 
The observations upon which he bases his cytological explanation 
of the fact that he finds no distinctly intermediate or Mendelian type 
of inheritance are as follows: 
»Die primären Bastarde. In der Prophase der ersten Reifungs- 
teilung kommt entweder gar keine Konjugation der artfremden Chro- 
mosomen vor, oder eine solche von einzehien Chromosomenpaaren. Im 
ersten Fall gehen alle Chromosomen selbständig in die Kernspindel ein, 
welche also die diploide Chromosomenzahl aufweist. Die Chromosomen 
teilen sich also äquationell. Eine Chromosomenreduktion findet 
also nicht statt. Werden dagegen diejenigen Fälle, in welchen eine 
Konjugation zwischen einzelnen Chroniosomenpaaren geschieht, mit 
in Betracht gezogen, so ist die erste Reifungsteilung eine kombinierte 
Äquations- und Reduktionsteilung . . . « (pag. 48). 
His text fig. D, pag. 71 shows clearly his conception of the rela- 
tion between the mode of inheritance and the behaviour of the chro- 
mosomes : 
“I. alternativer” (conjugation of all univalents at synaptic period) 
“II. intermediärer” (no conjugation), 
“III. kombiniert alternativer und intermediärer Vererbung” (one 
or more pairs conjugate). 
