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simple basis of "sensory" and "motbr" could not avoid leading 

 to many dogmatic positions concerning, the real character and 

 ultimate distribution of many fibres. An attempt to solve such 

 intricate problems through so mechanical a method could hardly 

 be otherwise than faulty, particularly when applied to the 

 specialised conditions of the mammalian nerves. A thorough 

 study of the less modified cranial nerves of the Ichthyopsida 

 is a necessary preparation for sound morphological work in the 

 higher field. 



The views of cranial nerves held by the neurologists of 

 to day were founded less than a decade since, but the germ of 

 the central idea is traceable to a somewhat earlier date. Gas- 

 kell in a series of publications ( 'S6, '88, '89) was making the 

 attempt to solve the metamerism of the head and the origin of 

 the vertebrate nervous system through a study of the nerves. 

 He took occasion to show that a spinal nerve not only embraces 

 the sensory and motor fibres of Bell, but that its structure, 

 distribution, and function, as well as the arrangement of its 

 central nuclei, lead to the divisibility of the nerve into two 

 parts. One part is somatic, innervating the external surface 

 of the body, and the muscles derived from the muscle-plates. 

 The other division is splanchnic, supplying the internal organs 

 and surfaces, and those muscles which Gaskell characterises as 

 "derived from the lateral plates of the mesoblast". Gaskell 

 attempted to show, further, that the cranial nerves arise from 



