The Allen and Greenough is still under construction;
so some links may not work quite the way you would expect.
341. The Genitive is regularly used to express the
relation of one noun to another. Hence it is sometimes called the
adjective case, to distinguish it from the Dative and the
Ablative, which may be called adverbial cases.
The uses of the Genitive may be classified as follows: -
1. Of Possession (§ 343).
2. Of Material (§ 344).