Meyer, Data of Modem Neurology. 313 



this method lies in the clearness of its problems and in the par- 

 allelism of its problems with those of the tasks of pathological 

 anatomy and of physiology. And just here the neurone-theory 

 in its broad and loose form is the most stimulating and work- 

 able hypothesis. 



The method of correllation of clinical observation and the 

 data of pathological anatomy has been discussed fully. For the 

 physician who is satisfied with a hasty diagnosis the warning 

 laid down may be superfluous. To him it does not matter 

 whether the sun turns round the earth or the earth round the 

 sun, as long as night is night and day is day and each comes in 

 due time ; but for the science of neurology it is essential that 

 correlations shall be made critically. We have already sum- 

 marized this point at the end of the preceding chapter. 



DESCRIPTION OF FIGURES. 



PLATE XX. 



Fig. 7. Sections of hemiplegia with degeneration of the direct and crossed 

 pyramidal tract. 



A. Cervical cord in infantile hemiplegia. Complete resorption of degen- 

 erated direct bundle and shrinkage of the whole side of the crossed tract. 



B. Cervical cord in hemiplegia of the adult. Greater stability of form and 

 greater neuroglia scar. 



PLATE XXI. 



Fig. 8. Section from a guinea pig in which the left hypoglossal nerve 

 had been torn out shortly after birth. From Forel's contribution to KoUiker's 

 Festschrift, 1891. 



/. /. m , left pneumogastric motor intact ; r. p. m., right pueumogastric 

 motor intact; /. hy., left hypoglossal nucleus degenerated ; r. hy., right hypo- 

 glossal nucleus and nerve intact; rp. raphe; IV, beginning of fourth ventricle. 



Fig. g. Section from a guinea pig in which the right pneumogastric nerve 

 had been torn out shortly after birth. From Forel's contribution to KoUiker's 

 Festschrift, i8gi. 



/. s. X., left sensory nucleus of n. X, terminal branches of n. X intact; r. 

 s. X., right sensory nucleus of n. X, cells crowded, terminations of n. X re- 

 sorbed ; /. m. X., left motor nucleus of n. X, intact ; r. m. X., right motor nu- 

 cleus of n. X, degenerated ; /. hy., left hypoglossal cells and nerve intact; r. 

 hy., right hypoglossal cells and nerve intact; IV, beginning of fourth ventricle. 



