Bei einzelnen sind die Nachkommen theils der einen, theils der anderen Stammpflanze näher gerückt, oder sie neigen sich sämmtlich mehr nach der einen oder der anderen Seite hin; bei einigen aber bleiben sie der Hybride vollkommen gleich und pflanzen sich unverändert fort.
With some individual hybrids the descendants partly approach one, partly the other parental plant more closely, or they lean more towards one or the other side all together; but in some, they remain perfectly similar to the hybrid, and propagate themselves without being changed.
partly = theils The manuscript originally had bald, which was replaced by theils. The latter expression suggests fixed proportions, whereas the former connotes a more random process.
without being changed = unverändert The manuscript has ungeändert (“unchanged”), which is more active. Mendel seems to have made this change following Carl Friedrich Gärtner’s description of such cases; see p. 40, s. 7.