506 



PHYSIOLOGY 



CHAP. 



rabbit is not capable of maintaining equilibrium either in standing 

 or in walking. 



The observations on rabbits and other small mammals were 

 only made during one to two days, beyond which he was unable to 

 keep them alive. They are important as showing that the motor 

 and sensory functions which persist can be carried out independently 

 of the parts of the brain that were destroyed, but they do not 

 permit us to ascertain how far the loss of function is due to 

 removal of the organs, or to the effects of operative traumatism. 



All-important and unique in the 

 literature of the subject are the re- 

 searches and observations of Goltz 

 (1892) on three brainless dogs which 

 he succeeded in keeping alive for some 

 time. The first lived fifty-seven days, 

 the second ninety-two days, the third 

 was killed by bleeding after eighteen 

 months. The right hemisphere was 

 destroyed in a single operation ; the 

 left in three operations ; the frontal 

 and parietal lobes were first removed, 

 next the temporal lobe, and lastly the 

 occipital. 



In the third decerebrated dog, on 

 which Goltz made minute observa- 

 tions which he carefully recorded, the 

 post-mortem examination by Schrader 

 showed as follows (Fig. 258) : medulla 

 oblongata and cerebellum perfectly 

 normal, but the pyramids had dis- 

 appeared; the left anterior quad- 

 rigeminal body was much flattened, 

 shrunken, softened, and greyish- 

 yellow in colour, and the left pos- 

 terior quadrigeminal body showed the same change to a slight 

 degree. The rest of the left fore-brain with the optic thalamus 

 measured 1/7 cm. in length; it consisted of a softened greyish 

 mass, which was mainly the remains of the corpus striatum 

 and thalamus. The remains of the right fore -brain with the 

 thalamus of that side measured 3 cm. in length. Besides the 

 degenerated portions of the corpus striatum and thalamus, a soft 

 brown residue of the cornu Ammonis could be seen. The right 

 optic nerve was smaller than the left and grey in colour, while 

 the colour of the left was normal. 



The phenomena manifested by Goltz' "brainless dog" are 

 therefore characteristic of an animal deficient not only in the 

 entire cortex of the fore-brain, but also in a large part of the 



FIG. 258. Brain from Goltz' celebrated 

 "brainless dog." (Explanation in 

 text.) 



