sentence1: In some (e.g. Castanea), the scales are developed into sharp spines, giving the nut protection from squirrels and other seed predators, while in others (e.g. most Quercus), they are not.
sentence2: In some (e.g. Quercus), the scales are developed into sharp spines, giving the nut protection from squirrels and other seed predators, while in others (e.g. most Castanea), they are not.