248 THE EVOLUTION OF MAN. 



from the large brain through the roof of both nasal cavities 

 into the cavities, and extends over the olfactory mucous 

 membrane. At the same time, by inversion of the nasal 

 mucous membrane, the minor cavities of the nose, which are 

 afterwards filled with air, and which communicate directly 

 with the two nasal cavities, arise (frontal cavities, cavities of 

 the sphenoid bone, jaw cavities, etc.). In this special stage 

 of development they occur only in Mammals.^"^^ 



The external nose is not developed until long after all 

 these essential internal parts of the olfactory organ have 

 been formed. The first trace in the human embryo appears 

 at the end of the second month (Figs. 238-240). Any 

 human embryo during the first month shows that originally 

 there is no trace of the external nose. It afterwards grows 

 out from the anterior nasal portion of the primitive skull. 

 The form of nose which is characteristic of Man does not 

 appear till a period far later. Much stress is usually 

 laid on the shape of the external nose as a noble organ, 

 occurring exclusively in Man ; but there are Apes which 

 have very human noses, as, for instance, the Nosed Ape 

 already mentioned. On the other hand, the external nose, 

 the fine shape of which is so extremely important to the 

 beauty of the facial structure, possesses in certain inferior 

 races of Man a shape anything but beautiful. In most 

 Apes the external structure of the nose remains undeveloped. 

 Especially remarkable is the important fact already cited 

 that it is only in the Apes of the Old World, in the Cata- 

 rhines, that the nasal partition wall (septiim) remains as 

 small as it is in Man ; in Apes of the New World it widens 

 considerably at the base, so that the nostrils open outwards 

 ^Platyrhini, p. 175). 



