THE EAR. 



the pinna is bounded by a prominent and incurved margin, the helix, which, 

 springing above and rather within the tragus, from the hollow of the concha, 

 surrounds the upper and posterior margin of the auricle, and gradually loses itself 

 in the back part of the lobule. Within the helix is another curved ridge, the 

 anthelix, which, beginning below at the antitragus, sweeps round the hollow of 

 the concha, forming the posterior boundary of that concavity, diverging above it 

 into two ridges. Between the helix and the anthelix is a narrow curved groove, 

 the fossa of the helix (fossa scaphoidea) ; and in the fork of the anthelix is a 

 somewhat triangular depression, the fossa of the anthelir (fossa triangular is). 



car-point (when present] 



crus anthelicis sup. 



Mix 



fossa triangularis 

 crus anthelicis inf. 



tragus 



I,. _ __ antitragus 



incisura intertragica 



lobulus 



Fig. 79. OUTER SURFACE OF THE RIGHT AURICLE. (After Arnold.) 



Ear-point ; Tubercle of Darwin. Slight projections are occasionally observed 

 in the human subject at the margin of the helix. One of these to which Darwin's 

 attention was drawn by Mr. Woolner, the sculptor, is of interest as representing the 

 much more distinct pointed extremity met with in the expanded ears of quadrupeds 

 (Darwin, " The Descent of Man "). The point in question is represented in the 

 sketch given in fig. 79 B. It is constant in the embryo of about the 6th month, 

 where it presents a relative extent of development which is permanent in certain 

 monkeys (Schwalbe). 



Considerable variation is met with in the size and shape of the pinna, 1 in its amount of 

 projection from the side of the head, in the extent of folding which it exhibits, and in the 

 size of the lobule, and this is not only in individuals of different races, but even in those 

 belonging to the same family. Attempts have been made to use these variations as a basis of 

 classification in criminal anthropology, but with results of very doubtful value. The lobule 

 is usually regarded as a human characteristic, but it is sometimes found fairly well developed 

 in anthropoids, and is often very little developed in man. 



Structure. The pinna consists mainly of yellow fibro-cartilage and integument, 

 with a certain amount of adipose tissue. It has several ligaments and small muscles 

 of minor importance. 



The sJcin covering it is thin, closely adherent to the cartilage, especially on the 

 concave aspect, and is covered with hairs which are .provided with large sebaceous 

 follicles. It also contains sweat glands on the convex aspect, but few or none on 



1 The relation of the transverse to the longitudinal measurement of the pinna is known as the ear- 

 index ( _ J and is employed in anthropometry. 



