96 SCIENCE PROGRESS 



The original passage of 1821 (Phil. Trans. R.S. p. 409) 

 reads thus : 



" Of the Trigeminus or Fifth Pair 



" From the nerve that comes off from the anterior ganglion 

 of the leech, and which supplies its mouth, we may trace up 

 through the gradations of animals a nerve of taste and mandu- 

 cation, until we arrive at the complete distribution of the 

 trigeminus in man (see Plate XXX. B.C.D. which are its three 

 grand divisions to the face). Here in the highest link, as in 

 the lowest, the nerve is subservient to the same functions. It 

 is the nerve of taste, and of the salivary glands, of the muscles 

 of the face and jaws, and of common sensibility. This nerve 

 comes off from the base of the brain in so peculiar a situation, 

 that it alone of all the nerves of the head receives roots both 

 from the medullary process of the cerebrum and of the cerebellum. 

 A ganglion is formed upon it near its origin, though some of 

 its filaments pass on without entering into the ganglion. 

 Before passing out of the skull the nerve splits into three 

 great divisions, which are sent to the face, jaws, and tongue. 

 Its branches go minutely into the skin and enter into all the 

 muscles, and they are especially profuse to the muscles which 

 move the lips upon the teeth." 



As republished in 1824 (An Exposition, etc., p. 96) the passage 

 reads : 



" Of the Trigeminus or Fifth Pair 



" From the nerve that comes off from the anterior ganglion of 

 the leech, and which supplies its mouth, we may trace up through 

 the gradations of animals a nerve of taste and manducation, until 

 we arrive at the complete distribution of the fifth, or trigeminus 

 in man (see Plate III., in which there are its three grand 

 divisions to the face). Here in the highest link, as in the lowest, 

 the nerve is subservient to the same functions. It is the nerve 

 of taste, and of the salivary glands ; of the muscles of the jaws, 

 and of common sensibility. This nerve comes off from the base 

 of the brain in so peculiar a situation, that it alone, of all the 

 nerves of the head, receives roots both from the medullary 

 process of the cerebrum and of the cerebellum. A ganglion is 

 formed upon it near its origin, though some of its filaments pass 

 on without entering into the ganglion. Before passing out of 

 the skull, the nerve splits into three great divisions, which are 

 sent to the face, jaws, and tongue. Its branches go minutely 

 into the skin and enter into all the muscles, and they are 

 especially profuse to the lips." 



