Book,  Paragraph

 1   I,  1 |  analogy. For there is a slight distinction of this sort, since even
 2   I,  2 |     faculty. Clearly, then, the distinction of sex is a first principle;
 3   I,  16|   enough to enable us to make a distinction of classes. And generally
 4  II,  4 |        animals who possess this distinction, for some (i.e. all those
 5  II,  6 |     animals in which exists the distinction of upper and lower, except
 6  II,  6 | locomotive animals in which the distinction of upper and lower does
 7  II,  6 |        by which the qualitative distinction is produced, and so the
 8 III,  1 |    wind-eggs of birds have this distinction of colour, for they contain
 9 III,  5 |         have a uterus, and this distinction obtains in all except two,
10 III,  5 |        would be strange if this distinction did not exist in the whole
11 III,  5 |          unless in any kind the distinction of sex does not exist),
12  IV,  1 |       imperfect in its kind the distinction is already made between
13  IV,  1 |         may be, even before the distinction is plain to our senses,
14  IV,  1 |       many animals in which the distinction of sex exists, and which
15  IV,  3 |      all the phenomena, (1) the distinction of sex, (2) why the female
16   V,  7 |  decided in accordance with the distinction postulated, the result will