Guenons may be regarded as some of the most typical of all monkeys, and those in which monkey-tricks attain their fullest development. They live more on fruits and seeds than either the guerezas or the langurs, which feed largely on leaves and the young shoots of trees. Guenons are indeed probably to some extent omnivorous, whereas the members of the other two groups are wholly herbivorous. This difference in the matter of diet is correlated with the presence of cheek-pouches and the simple character of the stomach in the guenons, whereas the other two groups lack pouches in the cheek, but, in compensation, have the stomach folded and divided in a complex manner. In their native forests green monkeys and their relatives associate in large troops, which keep up a constant chattering, and each of which is under the leadership and control of an old male. Each troop appears to have its own particular territory in the forest; and if one party intrude on the domain of its neighbour, a fierce contest takes place, which does not end until the invaders have been driven out or have proved themselves the stronger. A survival of this custom may be noticed even among monkeys in a menagerie, where each species or individual will take up one portion of the cage for its own particular use, and resolutely defend it against the other occupants of the enclosure. From the other members of the genus the patas monkey (_C. patas_) and its relatives are specially distinguished by their red colouring and large size, and they should perhaps form a genus by themselves. THE FOX (_Canis vulpes_ or _Vulpes alopex_) The fox enjoys a well-earned reputation for cunning and shrewdness, and especially for its capacity to adapt itself to changed conditions and its presence of mind and resourcefulness in emergencies. Nevertheless, it is possible to deceive even a fox. A well-known American naturalist relates, for instance, how he attracted a fox to within a few yards of his own position by imitating the squeaking of a field-mouse. For some distance he came cautiously skulking between the big tussocks of coarse grass, but for the last fifty yards he had to traverse open sward. When he had got half this distance he became suspicious, and began to think that the motionless, squatting naturalist was not a stump or a rock, whereupon, it is curious to note, that he at once ran to leeward of the suspicious object, thus showing that foxes, like many other animals, trust more to their sense of smell than to their sight.