94 JoUUNAl, OK CoMl'ARATlXK NeUKOUx; V. 



The problems of neurology resolve themselves into the 

 purely structural investigation, which appeals to microscope 

 and microtome, and physiological questions involving a 

 knowledge of the behavior of the living cell under the most 

 diverse conditions, as well as of the laws of composition of 

 function due to their interaction. Yet a higher class of 

 problems, which properly transcend the sphere of neurology, 

 as of all purely observational science, respecting the relation 

 of body and mind, can never be wholly ignored. 



In the study of all these questions the methods and results 

 of morphology must always guide the investigator, though 

 it is not less true that the solution of many of the vexed 

 riddles of morphology depends upon the recognition and 

 employment of neurological laws and generalizations. That 

 part of the field which is being cultivated with the most 

 zeal and success is the structural province. Yet in this 

 most promising department the accumulation of details has 

 too often proven unfruitful for the lack of a sufficiently com- 

 prehensive view of the entire field to enable the investigator 

 to appreciate the bearings of isolated facts. 



The objection once urged against the employment of 

 comparative data in the determination of the functions of the 

 human organs, i.e., that there can be no proof of homology 

 between the brain, of man and that of lower animals has been 

 removed by the researches of Keen, Lloyd, Nancrede and 

 Horsley, which prove the substantial similarity in function 

 of the various cortical areas in man and the higher apes. 



The brilliant success which even now attends operations 

 for the removal of localized cerebral disturbances based on 

 the data derived from experiments upon lower animals is 

 practical demonstration of the utility of the science, but in 

 the light of what has been done the future is palpitant with 

 suggestion. 



During the last few years the more general homologies 

 have been established within the group of vertebrates, and 

 such papers as that of Alborn on Petromyzon have laid the 



