86 



EVOLUTION AND DISEASE. 



A well-marked specimen of cervical auricle in a goat 

 is sketched in fig. 42 : these auricles are situated at a 

 spot corresponding to the external orifice of the third 

 branchial slit of the embryo. 



The auricles are not confined to any particular species 

 of goat ; the one sketched above is a cross between a 



FIG. 44. Magnified view of a section of a cervical auricle removed 

 from a baby's neck. C, cartilage ; M, muscle-fibre ; F, fat. 



Nubian and a common goat. In fig. 43 a sketch is 

 given of the head of an Egyptian goat (Hircus thebaicus], 

 made from life by Mr. R. E. Holding from a specimen 

 which was living in the Jardin des Plantes, Paris. 

 Their existence in the pig has been recorded, and a 

 horned sheep with two well-marked cervical auricles 

 is figured on page 63. 



