i8 



NA TURE 



[Novp:MiiER 7, 1901 



'be detected in the same figure, Nos. 13, 17, 31, and in Fig. i, 

 Nos. 9, 13, 15, 28, 29, 30, 35, 36, 38, 46. An ear of the same 

 type is shown in Fig. 4 ; it is a tracing from the ear of " Sally," 

 the chimpanzee, and is typical of her species. This may be 

 called the " chimpanzee type " of human ear. 



This nomenclature, of course, does not imply that people with 

 the orang-type of ear are related any more to the orang than the 

 chimp.inzee-type indicates an affinity to the chimpanzee. The 

 resembl.inces are due ta the fact that in the orang the external 

 ear has undergone marked retrograde changes : in the chimpanzee 

 ^the ear has retained its pristine development. The one marks 



Eoriz lielL\ 



•Asc. helix 



Tralus 



' Flc. s- — An Or.inR's Ea 



the ebb tide of retrogression, the other the full tide of develop- 

 ment : the corresponding types in man mark the same extremes. 

 The anatomical parts of the ears of the three great anthropoids 

 and man are the same (see Figs. 3, 4, 5 and 6), but in men are 

 found types exemplifying the retrograde changes which have 

 overtaken the ears of all orangs, and also examples of the full 

 development which marks the ears of chimpanzees. Curiously 

 enough the gorilla, like man, shows an amplitude in the varia- 

 tions of its ear, but on the whole it inclines towards the orang- 

 type. 



But what is meant by retrogression, and what by full develop- 

 ment of the ear ? The explanation entails a reference to the seven 

 parts which compose the outer ear. Each of the seven springs as 

 a separate part round the opening of the ear in the embryo, and 

 by the fourth month they have fused to form the whole structure. 



.Antihelix 



Asc.helix 



Fig. 4.— Ear of Clumpan/ec. 



Three of these parts surround the concha, or cavity, and opening 

 of the ear-passage, viz. the tragus, the antitragus and the anti- 

 hehx (sec Fig. 5). The remaining four parts form the circum- 

 ference of the ear, viz. the ascending helix — in front and above ; 

 the horizontal helix— above ; behind, forming the wide posterior 

 border of the ear— the descending helix ; and below— the lobule. 

 Now only one of these seven parts suflers markedly from progres- 

 sive or retrogressive changes, and that is the descending helix. In 

 Fig. 5 a human ear is represented — somewhat diagrammatically 

 with the descending helix fully developed ; that is to say the 

 descending helix is wide, expansive, and its margin is not inrolled ; 



NO. 167 I, VOL. 65I 



the ear of the chimpanzee (Fig. 4) shows similar characters in its 

 descending helix. On the other hand, the orang's ear (Fig. 3) 

 .shows the descending helix not only markedly reduced, but its 

 margin, like that of a cankered leaf, is inrolled. A reference to 

 the orang types in Fig. i (such as No. ii) and Fig. 2 will 

 show inrolling of the margin of the descending helix, similar 

 to that in the orang. The various degrees to which the in- 

 rolling may be carried is shown diagrammatically in Fig. 5. Four 

 degrees of inrolling are recognised, viz. o, ist, 2nd or 3rd degree. 

 It should be remarked, however, that the reduction in size of 

 the descending helix .and inrolling of its margin do not con- 

 stitute all the characters of tlie orang type — with these the de- 

 velopment of the ear .as a whole also shows reduction in size. 

 The height of the ear of a chimpanzee is nearly twice that of an 

 orang, yet the orang is the larger animal of the two. 



There is one prevalent conception of the human ear which 

 I believe to be a mistaken one, and which I wish to correct 

 now. It is usual to speak of it as a decaying structure. This 

 is remarkable, if true, for with the introduction of speech the 

 means of catching sound are more needed than ever. Although 

 the helix, especially the descending helix, which in mammals 

 generally makes up the greater part of their trumpet-shaped ears, 

 has undergone and is undergoing retrogression in man, that part 

 of the ear which bounds and deepens the concha, the antihelix 

 (Fig. 5), has reached a development in man which it never had 

 before. At least, no other primate shows such a development. 

 That is the change which appears to be going on in m.an now. 



- Crua of anuhclui 



Fig. 5. — Diagram of the humm ear. 



viz., that in him a new type of ear is being evolved in which the 

 antihelix plays the chief part in collecting sound-waves, while the 

 circumference — the outer helix— undergoes retrogression. In 

 this the orang-type of the human ear differs from the ear of the 

 orang ; in the orang the antihelix is in as retrograde a condition 

 as the other parts of the outer ear, even the crus of its antihelix 

 is only occasionally developed (Fig. 3) ; in the orang-type 

 of the human ear the antihelix is especially well developed. 



I should like to proceed at once and inquire into the relation- 

 ship which those two types of human ears bear to the mental 

 bias of the individuals in which they are found. But in order 

 to avoid the mistakes made by the followers of Lombrosa on the 

 Continent, it is necessary to allude to certain factors which have 

 a powerful influence in determining the type of the external ear. 

 I need not allude to age ; that influences shape to some extent, 

 but its effect is principally on its size. Schwalbe found that, 

 on an average, the length of the ear increases 20 mm. from the 

 twentieth to the eightieth year and the breadth at a correspond- 

 ing rate. The ears of old [leople are always large and hence 

 in my statistics I excluded those over sixty. This increase is a 

 factor which those who use the ear for identification purposes 

 should remember more than they do. 



Sex is a powerful factor. The following table (table i), in" 

 which are given the number of ears observed, the locality in 

 which they were observed, the sex of the individual and the 

 percentage in which the orang- and chimpanzee- types of ear 

 occurred, will show its influence. 



