THE SCAFFOLDING LEFT IN THE BODY 113 



Now, bearing in mind this theory of the origin 

 of ears, an extraordinary corroboration confronts us. 

 Ears are actually sometimes found bursting out in 

 human beings half-way down the neck, in the exact 

 position — namely, along the line of the anterior' 

 border of the sterno-mastoid muscle — which the 

 gill-slits would occupy if they still persisted. In 

 some human families, where the tendency to retain 

 these special structures is strong, one member 

 sometimes illustrates the abnormality by possessing 

 the clefts alone, another has a cervical-ear, while a 

 third has both a cleft and a neck-ear — all these, 

 of course, in addition to the ordinary ears. This 

 cervical auricle has all the characters of the 

 ordinary ear, " it contains yellow elastic cartilage, 



closes in the centre, the point of concrescence forming the 

 tympanic membrane. The remaining outer part of the first 

 gill-opening is the rudiment of the outer ear-canal. From the 

 inner part originates the tympanic cavity, and further inward, 

 the Eustachian tube. In connection with these, the three 

 bonelets of the ear develop from the first two gill-arches ; 

 the hammer and anvil from the first, and the stirrup from 

 the upper end of the second gill-arch. Finally, as regards 

 the external ear, the ear-shell (concha auris), and the outer 

 ear canal, leading from the shell to the tympanic membrane— 

 these parts develop in the simplest way from the skin-covering 

 which borders the outer orifice of the first gill-opening. At 

 this point the ear-shell rises in the form of a circular fold 

 of skin, in which cartilage and muscles afterwards form." 

 — Haeckel, Evolution of Man, Vol. il., p. 269. 



