366 Journal of Comparative Neurology and Psychology. 



to have associative connections with the anterior portions, they 

 are located posterior to the cerebellum. The inhibitory influ- 

 ences noticed especially during the first two or three days after 

 the operation, I attribute to the loss of association fibers. The 

 centers for swallowing, the sense of equilibrium, and heart ac- 

 tion seem to have only slight associative connections with these 

 anterior parts. It appears that the greater portion of the func- 

 tions performed exclusively and in a more specialized degree by 

 the cerebellum of the dog is performed by the anterior third of 

 the medulla of the frog. It was interesting to note after uni- 

 lateral excision of the medulla, that the abnormal position of the 

 spine and the rotatory movements were closely related in time 

 of appearance, and also that the position of the body and legs 

 were closely related to one another and to the two former phe- 

 nomena. The rotatory movement around the sagittal axis was 

 the first phenomenon to appear and also to disappear, whereas 

 the sensory ataxia and the atonia became apparent only when 

 the forced rotatory movements became less vigorous. I at- 

 tribute the forced rotatory movements principally to the direct 

 acute disturbance caused by the excision of an important com- 

 ponent of the neuron-complex pertaining to the geotropic 

 sense. The fading away of the forced rotatory movements ac- 

 cordingly would mark the disappearance of this acute disturb- 

 ance owing to the function vicariously assumed by paths formed 

 by the union of the intact neurons of the broken neuron -com- 

 plex with other neurons surrounding them. When these new 

 paths were fully formed and the acute symptoms had in part 

 subsided, the atonia and sensory ataxia became more prom- 

 inent. 



The absence of abdominal respiratory movements on the 

 homonymous side after unilateral medullar excision anterior to 

 the calamus scriptorius proves that the centre for abdominal 

 respiration is present in the medulla above the calamus and that 

 its centrifugal fibers do not appreciably cross, moreover, that 

 it does not control the laryngeal and narial respiratory move- 

 ments, since these still persist bilaterally and normally. The 

 loss of the eye reflex to pressure on the homonymous side is to 



