122 Journal of Comparative Neurology. 



junction of dorso-lateral and ventro-lateral lamina. C. Type of 

 the facial nerve — it originates from a lateral cell-nest of the 

 basal plate ; runs towards the median line, then turns through 

 a 'knee' around the median cell-nest (abducens group) and out- 

 ward between the dorsolateral and the ventro-lateral part of the 

 lateral wall of the medulla. D. The type of the fourth nerve — 

 the cell-nest lies in the basal lamina ; from there the fibers grow 

 outward, into the roof of the tube and after decussating with 

 the bundle from the opposite side, come to the surface. 



8. The cells of the spinal ganglion have at first no long 

 processes ; then follows a stage when every cell is bipolar, and 

 later on, the spinal ganglion cell is characterized by the pres- 

 ence of two fibrillary axis-cylinder-processes which leave 

 the cell in opposite directions and to which the cell- 

 body takes an eccentric position. The central processes of 

 the spinal cells grow towards the medullary tube and remain to 

 a great extent on its surface, forming a longitudinal tract. 



9. In the spinal cord the ingrowing sensory roots form 

 the primary posterior column; within the ' brain ' the so-called 

 ' ascending roots', the roots of the pneumogastric, glosso- 

 pharyngeal, nerve of Wrisberg and the fifth are, as it were, the 

 posterior column-formation of the medulla. 



10. Not all the sensor)^ root fibers of the neural tube 

 grow simultaneously. At first there are fewer fibers than later. 

 This holds also for the central tracts, the anterior commissures 

 arid the antero-lateral columns. 



11. The ' ascending roots ' are first quite short and grow 

 successively longer. 



12. The peripheral nerve-trunks too grow gradually. 



In the above studies we have the root and the soul of the 

 neurone-theory. It is, however, nothing but fair to say that 

 Ramon y Cajal, the greatest promotor of neurology that Spain 

 ever has produced, should be mentioned as the chief confirmer 

 of the .same concept. This is certain that none has discovered 

 and demonstrated more individual details in confirmation of the 

 views of Forel and His than this indefatigable Madrid histolo- 

 gist, and as he says himself, he has done what neither His nor 



