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TABLE XXX. 



Systematic Sukvey op the Chief Phylogenetic Stages of tmk 



Human Nose. 



First Stage : Nose of the earlier Primitive Fishes. 



The nose is formed by a pair of simple skin-grooves (nose-pits) in the 

 onter surface of the head (like those which are now permanently retained 

 by the lower Selachians). 



Second Stage : Nose of the more recent Primitive Fishes. 



Each of the two blind nasal grooves becomes connected by a furrow 

 (nasal-furrow) with one end of the mouth (as is yet permanently the case in 

 the higher Selachians). 



Third Stage : Nose of the Dipneusta. 



The two nasal furrows change, in consequence of the coalescence of their 



edges, into closed canals (primary nose-canals), which open at their front 



ends, within the soft edges of the lip, into the primary mouth-cavity ; as is 



yet permanently the case in the Dipneusta and the earlier lower Amphibia 



{Sozobranchia). 



Fourth Stage : Nose of Amphibia. 



The inner openings of the nasal canals penetrate further back into the 

 primary mouth-cavity, so that they are surrounded by hard bony portions of 

 the jaw (as is yet permanently the case in the higher Amphibia). 



Fifth Stage : Nose of the Protamnia. 



The primitive mouth-cavity, into which both nasal canals open, separates, 

 in consequence of the formation of a horizontal partition (the palate-roof), 

 into an upper nasal cavity and a lower (secondary) mouth-cavity. The 

 formation of the spougy bones of the nose commences (as in the earlier 

 Amnion Animals). 



Sixth Stage : Nose of the earlier Mammals, 



Tlie simple nose-cavity separates, in consequence of the development of 

 a vertical partition wall (the "plough," vomer), into two distinct nose-cavities, 

 each of which is occupied by one of the nasal canals (as is yet the case in all 

 Mammals). The spongy nose-bones differentiate. 



Seventh Stage : Nose of the more recent Mammals. 



Within both nose-cavities the development of the spongy bones proceeds 

 further, and an external nose begins to form. 



Eighth Stage : Nose of the Catarhine Apes. 



The internal and the external nose attain the full development ex- 

 clusively characteristic of Catarliine Apes and of Man. 



