These types almost always characterise either the great centres of appearance, or the secondary centres or geographical regions. Not to mention mammals, I must remind my readers that Australia has its marsupials; South Australia, the ornithorynchus; polar America, the musk-ox; central America, the edentata; Africa, the giraffe; Asia, the yak; the Cape, the gnu; Madagascar, the makis and aye-aye; the Gaboon, the gorilla, etc. Man, also, is evidently an exceptional or aberrant type among mammals. He, alone, is constructed for a vertical position; he, alone, has true hands and feet; he, alone, exhibits the highest degree of cerebral development, and possesses that superiority of intelligence which makes him master of all around him. To allow that the human type, though the most perfect of all types, the exceptional genus in the midst of all others, has come into existence in several centres of appearance without characterising any, would be to make him a solitary exception. However strong may be our polygenistic tendencies, and however many species we may admit, we cannot help acknowledging that the original localisation of the human genus in a single centre of appearance and the characterisation of this centre by him are the logical consequence of all the facts attested by zoological geography. With still greater reason the monogenists will consider the privileged species which predominates over all others as one of those special types which characterise the centre, or the region in which they have appeared, as the ornithorynchus, the aye-aye, and the gnu characterise South Australia, Madagascar and the Cape. Finally, the laws of zoological geography lead us to consider the human species as unmistakably characteristic of a single centre of appearance. Moreover, they justify us in concluding that this centre cannot have been of greater extent than that of the gorilla and the orang. VIII. Is it possible to go still farther and to endeavour to determine the geographical position of the human centre of appearance? I cannot here enter into the details of this problem. I shall confine myself to determining its meaning, and to indicating the probable solutions of it from the data of science of the present time. I must observe, in the first place, that in considering an animal or vegetable species, even those whose area is most circumscribed, no one thinks of trying to discover the precise spot upon which it may have first appeared. There is always something very vague in such a determination and it is necessarily approximative. It is still more difficult when the species in question is of universal distribution. Within these limits we are justified in at least forming conjectures which, as such, have a certain amount of probability.