Die den einzelnen Verbindungen vorausgesetzten Zahlen geben zugleich an, wie viele Pflanzen mit der entsprechenden Färbung in die Reihe gehören.
The numbers put in front of the individual conjunctions indicate in addition how many plants with the corresponding colouration belong to the series.
conjunctions = Verbindungen See p. 10, s. 14.
in addition = zugleich Bateson has “also”, Sherwood do not translate this adverb at all. Mendel probably just continues on the previous sentence which also explained a feature of the table, namely that it has nine fields, each corresponding to a colour. In both cases, Mendel points out that certain features of the table are not just accidental results of the combinatorial operation from which he produced it, but that they actually carry specific biological meanings.
colouration = Färbung See p. 10, s. 8.