أو غير متناهية كأفراد الإنسان والفرس والغنم
Or without a finite limit, as in the individuals of humans, horses and sheep.
The illustrative purpose is to show indefinitely extendable multiplicity for kinds whose concepts are not confined to a pre-set count of specimens. Any new human can be human; any new horse can instantiate horsehood.
This does not assert that an actually infinite number of people or animals exists. The lesson concerns the open applicability of a universal, not an empirical census.