616 PHRENOLOGY: OLD AND NEW. 



is as obscure now as ever it was." It must not be forgotten, how- 

 ever, that it was Prochaska himself who first fully described the 

 nature of ' reflex movements.' " The sensorium commune,''^ he 

 says (loc. cit. p. 446), " reflects the sensorial impressions into motor 

 by definite laws peculiar to itself, and independently of conscious- 

 ness." Prochaska, moreover, recognized that the same kind of 

 process might take place in the systemic ganglia, since he says 

 (p. 438) : " It seems probable, therefore, that besides the sensorium 

 commune, which we conjecture to be in the medulla ohlongata, 

 'medulla spinalis, pons Varolii, and. crura of the cerebrum and 

 cerebellum, there are special sensoria in the ganglia and plexuses 

 of the nerves, in which external impressions ascending along the 

 nerves are reflected, that need not ascend all the way to the senso- 

 rium commune, to be reflected thence." 



The space available in this work does not permit of an 

 attempt to trace, even in hare outline, the successive steps 

 hy which during the last hundred years we have been 

 slowly tending to acquire a more exact (though still wholly 

 inadequate) knowledge of the Functions of different parts 

 of the Brain. Something of this sort may, however, be 

 gathered from the work of Vulpian* on the " Physiology of 

 the Nervous System," and from other sources. What has 

 here been already said will indicate how much required 

 to be done ; and what is about to he said will give some 

 faint noUon as to the present paucity of real knowledge, 

 and as To the need in which we stand of much further 

 light in many directions. 



Having considered the relations of the Cerebral Hemi- 

 spheres with one another, with the Cerebellum, and with 

 the halves of the body, the reader's attention must now 

 be limited to the Hemispheres themselves, in order that he 

 may learn, in this and in the next chapter, something of 

 what has been made out concerning the parts of these all- 

 important organs which appear to be more especially con- 

 * " Lecons sur la physiologic du systeme uerveux," 1866. 



