Versuche, welche in dieser Beziehung mit zwei Pisum-Arten angestellt wurden, weisen darauf hin, dass es für die Auswahl der tauglichsten Individuen zu dem Zwecke der weiteren Befruchtung einen grossen Unterschied machen könne, welche von zwei Arten in die andere umgewandelt wird.
Experiments, which in this respect were carried out with two Pisum-species, indicate that it could make a big difference for the selection of the most suitable individuals for the purpose of further fertilisation which of the two species is being transformed into the other.
Pisum-species = Pisum-Arten See p. 6, s. 14.
could = könne One would expect the indicative here, not the subjunctive. Mendel is again formulating with more caution than necessary.
most suitable = tauglichsten In the manuscript, this adjective was inserted later.