It is advisable to explain this phenomenon by reference to examples, and I will take the point of specialisation first. Even where industrial arts have advanced far beyond the primitive stage we are considering, we have the case of the Ahts, with whom "though living only a few miles apart, the tribes practise different arts and have apparently distinct tribal characteristics. One tribe is skilful in shaping canoes, another in painting boards for ornamental work, or making ornaments for the person, or instruments for hunting and fishing. Individuals as a rule keep to the arts for which their tribe has some repute, and do not care to acquire those arts in which other tribes excel. There seems to be among all the tribes in the island a sort of recognised tribal monopoly in certain articles produced, or that have been long manufactured in their own district. For instance, a tribe that does not grow potatoes, or make a particular kind of mat, will go a long way year after year to barter for those articles, which if they liked they themselves could easily produce or manufacture."[312] The remarkable case of the Todas specialising in cattle rearing and dairy farming is another example. Other people, both higher and lower in civilisation than the Todas, keep cattle and know the value of milk, but it is reserved for the Todas alone to have used this particular economic basis of their existence as the basis also of their social formation and their religious life.[313] The result is that they neglect other forms of social existence. They are not totemists, though perhaps they have the undeveloped germs of totemistic beliefs.[314] Their classificatory system of relationship makes their actual kinship scarcely recognisable; they "have very definite restrictions on the freedom of individuals to marry," and have a two-class endogamous division, but their marriage rite is merely the selection of nominal fathers for their children.[315] Throughout the careful study which we now possess, thanks to Dr. Rivers, of this people, there is the dominant note of dairy economy superimposing itself upon all else, and even religion seems to be in a state of decadence.[316] I do not know that anywhere else could be found a stronger example of the results of extreme specialisation upon the social and mental condition of a people. As a rule such specialisation does not extend to a whole people, but rather to sections, as, for instance, among the Gold Coast tribes of Africa who "transmit the secret of their skill from father to son and keep the corporation to which they belong up to a due degree of closeness by avoiding intermarriage with any of the more unskilled labourers,"[317] and Dr. Bucher, who has worked out many of the earliest conditions of primitive economics, concludes that it may be safely claimed that every "tribe displays some favourite form of industrial activity in which its members surpass the