There are two very distinct lines of thought among these archæologists: the first is shown in the tendency to regard the industries as mainly _autochthonous_, or as following local lines of development; the exponents of this theory dwell most strongly on the transitions between the Mousterian, the Aurignacian, and the Solutrean industries. For example, the chief object of Schuchhardt's tour(9) through the Palæolithic stations of Dordogne was to observe the transitions from one period to another and the evidence afforded of successive changes of climate. This writer is impressed with the transitions; he notes that the typical curved knives of the Abri Audit furnish a transition from the Mousterian scrapers to the Aurignacian 'points' of La Gravette and La Font Robert; that the Solutrean takes up all the fine threads of the Aurignacian culture and spins them further into Magdalenian times. Thus we get an Aurignacian-Solutrean-Magdalenian industrial cycle which is comparable to the Chellean-Acheulean-Mousterian cycle. Breuil, on the other hand, from the archæologist's standpoint--because he is not especially interested in the matter of racial development--is a strong exponent of the idea of _successive invasions_ of cultures, either from the south or Mediterranean region or from the central region of Europe, which he calls the 'Atlantic'; and he distinguishes sharply between these two great areas of Upper Palæolithic evolution, namely, the _southern_ and the _central_ European, pointing out that it was only after the establishment of more genial climatic conditions, like those of modern times, that there was an added element of northern or Baltic invasion. Certainly the archæologic testimony strongly supports this culture-invasion hypothesis and it appears to be strengthened in a measure by the study of the human types, although this study has not progressed beyond the stage of hypothesis. When the Upper Palæolithic races have been studied with as close attention as those of the Lower Palæolithic we may be able to establish positively the relation between these human types and the advance of certain cultures and industries. DISTRIBUTION OF UPPER PALÆOLITHIC HUMAN FOSSILS Our present view, as drawn from a consideration of the facts before us, is that western Europe in Upper Palæolithic times was entered by four or five distinct races, all belonging to _Homo sapiens_, only three of which became established: 5. The _Furfooz_ (Ofnet, and [?] Grenelle) _race_, extremely broad-headed, entering central Europe possibly from central Asia, bringing an Azilian culture, without art or developed flint industry. (Alpine type.) 4. A _dolichocephalic race_ with a narrow face, associated with the Furfooz race, either connected with the Brünn and Brüx, or an advance wave of one of the dolichocephalic Neolithic races. (Mediterranean type.)