Book 10
6
Male and female are attributes peculiar to the animal, but not in virtue of its substance; they ar material or physical. Hence the same semen may, as the result of some modification, become either female or male.
6
We have now stated what to be other in species means, and why some things differ in species and others do not.
1
Since contraries are other in form,It appears that in this chapter (apart from 5, which may be a later addition) the terms εἶδος and γένος are used in a non-technical sense. Cf. Ross on Aristot. Met. 1058b 28. and the perishable and imperishable are contraries (for privation is a definite incapacity), the perishable must be other in kind than the imperishable. But so far we have spoken only of the universal terms; and so it might appear to be unnecessary that anything perishable and imperishable should be other in form, just as in the case of white and black.
2
For the same thing may be both at the same time, if it is a universal (e.g, man may be both white and black); and it may still be both if it is a particular, for the same person may be white and black, although not at the same time. Yet white is contrary to black. But although some contraries
