482 COMPARATIVE PHYSIOLOGY. 



such knowledge be confined to any single form of the organ. 

 There is only one way by which this can be attained : dissection, 

 with the help of plates and descriptions. The latter alone fre- 

 quently impart ideas that are quite erroneous, though they 

 serve an especially good purpose in helping to fix the pictures 

 of the natural objects, and in reviving them when they have 

 become dim. 



It is neither difficult to obtain nor to dissect the brain of the 

 fish, frog, bird, etc. Valuable material may be saved and the 

 subject approached profitably, if, prior to the .dissection of a 

 human brain, a few specimens from some group or groups of the 

 domestic animals be examined. However useful artificial brain 

 preparations may be, they are so far from nature in color, con- 

 sistence, and many other properties, that, taken alone, they cer- 

 tainly may serve greatly to mislead ; and we hope the student 

 will allow us to urge upon him the methods above suggested 

 for getting real lasting knowledge. The figures given below 

 may prove helpful when supplemented as we advise. 



The great difference in total size, and in the relative propor- 

 tion, situation, etc., of parts, will, however, be obvious, from the 

 figures themselves ; and as we have already pointed out more 

 than once, the preponderance of the cerebrum in man must 

 ever be borne in mind in the consideration of his entire organi- 

 zation, whether physical, mental, or moral. 



ANIMALS DEFRIVIiD OP THE CEREBRUM. 



The cerebrum may be readily removed from a frog, without 

 producing either severe prolonged shock or any considerable 

 hasmorrhage. Such an animal remains motionless, unless 

 when stimulated, though in a somewhat different position from 

 that of a frog, having only its spinal cord. It can, however, 

 crawl, leap, swim, balance itself on an inclined plane, and when 

 leaping avoid obstacles. One looking at such an animal per- 

 forming these various acts would scarcely suspect that any- 

 thing was the matter with it, so perfectly executed are its move- 

 ments. We are forced to conclude, from its remaining quiet, 

 except when aroused by a stimulus, that its volition is lost; but, 

 apart from that, and the fact that it evidently does not see as 

 well as before, it appears to be normal. It has no intelligent 

 directive power over its movements. It remains, therefore, to 

 explain how it is that they are so much more complete, so 



