The sense of smell is one of the oldest developed senses, as well as one of the most important. Outside of the subphylum Vertebrata, the class Mammalia has the greatest olfactory perception and the most specialized nose. As in some other vertebrates, the sense of smell is distinct in mammals, but at the same time unlimited in its ability to differentiate between odors. The first to notice the importance of scent glands in mammals were perfumers. These different glands produced odors of musk, civet, castor oil and ambergris. Musk comes from the preputial glands of the musk deer, civet from the anal glands of the civet, castor oil from the castor gland of the beaver, and ambergris from the intestines of the sperm whale (Macdonald and Brown 1985). Although the olfactory lobes are not as large as in many lower vertebrates, as has already been said, in general the olfactory organs and structure are well developed in mammals. The level of development correlates with the animal's habits. This means that animals that rely more on olfaction in their behavior have greater sensory capabilities. Based on this idea, the uses of olfaction in mammals are numerous. One of these uses, which includes many different behaviors, is social functioning. Odors can be used to convey messages within a population and these can be conditioned by experience (Jameson 1921). When encountering strangers of the same species, there are 3 basic patterns of olfactory investigation. These naso-anal, naso-genital and naso-nasal contact points are where investigations most often take place (Macdonald and Brown, 1985). For example, when prairie dogs fight or are irritated, their anal glans gives off a strong musky odor that is due to other... middle of paper ...... being around males and females of the same species to mate. to the olfactory senses (Young 1975). In some mammals, males can smell a female from afar and will travel many miles just to mate with her. In this way, the male is attracted to the female, which is especially true for solitary mammals that spend most of their lives alone. Mammals also use smell to recognize the sex of another individual (Macdonald and Brown, 1985). This is why we don't usually see males trying to mate with other males, or vice versa. Again, in conferring with the second of Doty's reproductive olfactory categories, males emit olfactory information that reinforces the aggressive tendencies of rivalry males from the same territory to demonstrate dominance. The exact opposite was observed in women. They emit information that deters aggressive tendencies (Jameson 1921).