THE BRAIN. 233 



TONGUE. 

 Human Monkey Dog Cat Mouse. 



If a perpendicular section of the human tongue be 

 obtained, we shall see that it consists of a free surface, 

 covered with structures analogous to those of the skin, a 

 cutis or corium y on which are placed papillae, which are 

 more developed in the rough tongue of the Dog and the 

 Cat than in the human subject; consequently an injection of 

 the dog's tongue is a more beautiful object. The fungi- 

 form papillae spread out in looped capillaries, whilst on the 

 surface beneath is seen an intermediate plexus of minute 

 vessels. The artery and its vein are distinctly visible in 

 each papilla, with the attendant nerve, 



THE BRAIN. 



Cat Rabbit Mouse, &c, &c. 

 OR, SECTIONS OF SPINAL CORD OR GANGLIA. 



"We touch any slide of Brain reverently, for we stand 

 here upon the border-land between the visible aud the 

 invisible, the known and the unknown, whether it be of 

 animal instinct or human reason, whose seat lies here. 



Beautiful .are these delicate capillaries, spreading round 

 and over each convolution of the brain ; strange are these 

 stellate forms of nerve- corpuscles imbedded in a dimly- 

 shaded or granular substance. Nerve fibres ramify and 

 interlace nerve force flies along each fibre with immea- 

 surable velocity. We know that, chained within this 

 complex nerve system, the living soul goes to and fro in 

 contact with the outer world, upon the countless paths 

 which issue from the twelve pair of cerebral nerves and 

 thirty-one spinal nerves j each of these have a double fibre 

 of sensation and of motion ; they are separate, yet sheathed 

 together ; if we cut one of them, the power of movement is 

 gone, whilst sensation remains ; if we cut the other, then 

 convulsive, irregular movement stirs a limb which can no 

 longer feel. We know that, flashing from the invisible 



