E2L5
Lemma — Part II
Latin
Si partes individuum componentes majores minoresve evadant, ea tamen proportione ut omnes eandem ut antea ad invicem motus et quietis rationem servent, retinebit itidem individuum suam naturam ut antea absque ulla formæ mutatione.
English (Elwes 1883)
If the parts composing an individual become greater or less, but in such proportion, that they all preserve the same mutual relations of motion and rest, the individual will still preserve its original nature, and its actuality will not be changed.
Modern English
If the parts composing an individual become greater or smaller, but in such proportion that they all preserve the same ratio of motion to rest relative to one another as before, the individual will likewise retain its nature, without any change of form.