Werden zwei Pflanzen, welche in einem oder mehreren Merkmalen constant verschieden sind, durch Befruchtung verbunden, so gehen, wie zahlreiche Versuche beweisen, die gemeinsamen Merkmale unverändert auf die Hybriden und ihre Nachkommen über; je zwei differirende hingegen vereinigen sich an der Hybride zu einem neuen Merkmale, welches gewöhnlich an den Nachkommen derselben Veränderungen unterworfen ist.
When two plants that are constantly different in one or more traits are joined through fertilisation, the traits common to both — as numerous experiments prove — devolve without change to the hybrids and their descendants; two differing traits, in contrast, unite on the hybrid to form a new trait that usually is subject to changes in their descendants.
constantly different = constant verschieden; two differing = je zwei differirende Mendel is expressing himself in a complicated way here; “constantly different” (constant verschieden) in the first part of the sentence, up to the semicolon, refers to traits that all members of a particular group of plants share and that jointly distinguish them from other such groups of plants (this is the taxonomic sense of “constant”). The two “differing” (differirende) traits referred to in the second part of the sentence, in contrast, designate two such traits that constitute a contrasting pair of variants of one and the same character; in modern parlance, one would speak of a “character pair”; see the following sentence and p. 5, s. 5.
joined = verbunden Both Bateson and Sherwood have “crossed”. Verbunden derives from the verb verbinden; see p. 10, s. 14.
devolve … to the hybrids = gehen auf die Hybriden … über Both Bateson and Sherwood translate this as “are transmitted”. This is one of the few instances, in which Mendel is using metaphors of inheritance. We translate the intransitive übergehen auf with “devolve to”. The resulting allusion to processes of transmission and inheritance can be justified by the fact that it is quite common in German to use übergehen auf in exactly this sense, as an intransitive verb (i.e. a verb without a direct object) denoting the transmission of intangible goods, like rights, titles or privileges. That Mendel preferred this verb over vererben (to inherit; see p. 14, s. 1), which allows for transitive use, is remarkable.
unite = vereinigen See p. 41, s. 6.
on the hybrid = an der Hybride See p. 10, s. 10.