[B55v]

Say Dormouse only 1 species, therefore probably wd not range over whole of Grt Britain. Mus having several species, some one or more of them wd probably range over whole country & wd be numerous in individuals. This shows that the abstraction of called genus mus is well adapted to country, ie that something runs through genus several species in common, adapting it to physical & organical conditions "organic conditions" of area

[B55vv]

In a country where several species of a genus exist, it may predicated, that some will range far, & occupy every part., & so be likely to be parent of old form, spread still further. This also harmon[ise] with larger genera, being larger simply not having been exterminated; because conditions are favourable.