Gelingt es, eine Keimzelle mit einer ungleichartigen Pollenzelle zu verbinden, so müssen wir annehmen, dass zwischen jenen Elementen beider Zellen, welche die gegenseitigen Unterschiede bedingen, irgend eine Ausgleichung stattfindet.
If one succeeds in joining a germ cell with a pollen cell of different kind, then we must suppose that some compromise is taking place between those elements of the two cells that condition the mutual differences.
germ cell = Keimzelle See p. 24, s. 4.
of different kind = ungleichartigen Bateson and Sherwood have “dissimilar”. But the issue here is not similarity, but difference in kind or even species (see previous sentence).
successfully = Gelingt es Bateson has “If it chance”. Mendel’s exact phrasing is significant, because it indicates that he believed that attempts to unite gametes of different kind are not always successful, i.e. either yield no offspring at all, or only infertile offspring.
compromise = Ausgleichung Mendel chooses a term here, whether consciously or subconsciously, that had strong political undertones at the time of writing. The re-establishment of Hungarian autonomy in the dual monarchy of Austria-Hungary in 1866 is known as the Ausgleich. Reports in the daily press in 1865 used this term already; see Die Presse, Wien and Brno (Brünn), 18, no. 16 (16/01/1865), p. 2: “The compromise with Hungary will probably force the government to take back some steps” (Der Ausgleich mit Ungarn dürfte die Regierung nöthigen, manchen Schritt zurückzuthun). Available at ANNO (AustriaN Newspapers Online), http://anno.onb.ac.at.
elements = Elemente See p. 41, s. 6.