SOCIETY OF THE UNIVERSITY OF ABERDEEN. 235 



cess which can be observed in the ear of all primates. In this 

 mammalian order there is a rivalry between the helix and anthelix 

 as to which will play the chief part in forming the external ear. In 

 the orang type is to be seen the pre-eminence of the anthelix ; in the 

 chimpanzee type, the helix. In man and the gorilla the majority of 

 individuals show forms between these extremes ; in the remarkable 

 ear of the gibbon (which is set at a peculiar angle, and has its lobule 

 undifferentiated from the tissues of the cheek, see Figure 5 B) one 

 finds, in the majority of individuals, a type which resembles the chim- 

 panzee rather than the orang. Schwalbe is the only writer who has 

 rightly recognised the nature of the change at work in the ear of man, 

 namely, that it is not a rudimentary or vestigial structure, but one in 

 which a great transformation is taking place, whereby the anthelicial 

 part is superseding and replacing the helicial part in forming a re- 

 ceiver for sound waves. 



In Table V. I reproduce the results I obtained as regards the 

 frequency with which the orang and chimpanzee types occur in the 

 various groups of people examined. From that Table it will be ob- 

 served that I attempted to distinguish six types in all, but saving 

 the two types mentioned the orang and chimpanzee (named large 

 chimpanzee in Table) I regard the others as of little value. The 

 type distinguished as the average human type lies, as regards its 

 characters, in an intermediate position to the orang and chimpanzee 

 types. At the commencement I was impressed with a type of ear, 

 which in all its characters, save its size, resembled the chimpanzee 

 type ; I named it the small chimpanzee, but its distinction frequently 

 caused me perplexity and difficulty (see Fig. 6). The type called cer- 

 copitheque was one in which the ear was, as in most cercopithecus 

 monkeys, as broad in its lower as in its upper part, and its helix was 

 not inrolled, but it too I found difficult to discriminate. In the ano- 

 malous group I placed ears which were abnormal in form, or could 

 not be classified with any of the other five groups. 



