SOCIETY OF THE UNIVERSITY OF ABERDEEN. 



225 



I therefore resolved to keep a record of these types, but I was 

 not then aware o* what I learned later, that the orang type represents 

 an extreme degree of retrogression, 

 while the chimpanzee ear represents an 

 opposite stage, viz., one which is at 

 its fullest degree of development. 

 Later I shall recur to these two con- 

 trasted types of ear and give more 

 exact definition of their characters and 

 the meaning of these characters. These 

 were distinct types, but they included 

 less than 40 per cent, of the whole 

 how were the others to be classified ? 

 It would have been wiser to group all 

 that remained into one class, but I 

 sought to divide the remaining 60 per cent, into four groups : 



Fig. 4. The ear of the chimpanzee (A) 

 and of the "chimpanzee" type in 

 man (B), seen on a full face view. 



A 



B 



Fig. 5. Ear of gorilla (A), of gibbon (Hylobates lar) (B), and of lemur (Nyctipithecus tardigradus) 

 (C). a, root of helix ; b, ascending helix ; c, horizontal helix ; d, descending helix ; e, anthelix, 

 f, antitragus ; g, tragus; h, lobule. The ear of the lemur Y, reproduced for comparison with 

 that of the gibbon. The gibbon is seen to retain the lemurine form of implantation, the 

 lobule being undifferentiated from the tissues of the cheek. 



29 



