384 



Scientific Proceedings (124). 



Our results have mainly shown that considerable portions of 

 the corpora striata of dogs may be destroyed by our method with- 

 out producing marked neurological disturbances. Following 

 considerable destruction of the caudate and lenticular nuclei we 

 have seen animals remain apparently normal for several months. 

 This has occurred even when portions of the nuclei on each side 

 of the head were simultaneously destroyed. However, three to 

 five days following the treatment we have noted in several cases, 

 hypertonicity, tremors, and a certain clumsiness in locomotion. 

 Following these symptoms we have noted prompt compensatory 

 adjustment, so that within a short time the animal is apparently 

 again normal and remains so. 



Clinically, the function of the corpus striatum is believed to 

 be the control of automatic associative movements, and we be- 

 lieve that the symptoms we observed in our dogs are manifesta- 

 tions of disturbances in that mechanism. 



We believe that our method of destruction due to radium 

 emanation will prove of considerable value to the study of locali- 

 zation of functions in the basal ganglia of the brain. 



187 (1934) 



An hypothesis of the mechanism by which normal rhythm is 

 restored in atrial fibrillation. 



By HUBERT MANN. 



[New York City.] 



The abrupt change from atrial fibrillation or flutter to normal 

 sinus rhythm has become rather familiar to us since the use of 

 quinidin. In spite of our greatly improved knowledge of the 

 mechanism of fibrillation and flutter the exact way in which normal 

 rhythm supersedes these arrhythmias is still a matter of specula- 

 tion. The most prominent explanation, offered by Lewis, 1 has 

 recently been considerably modified 2 and is still rather unsatisfac- 

 tory because it fails to take into consideration events that may 

 be taking place in the region of the sinu-atrial node. 



1 Lewis, T., Brit. Med. Jour., 1921, 514. 

 ■ Lewis, T., Heart, 192, ix, 55. 



