HEART, CIRCULATION, AND BLOOD I77 



myasthenia gravis occurs in man when the thymus persists in adukhood or 

 when it swells up. Thymus extract appeared to have a similar effect on 

 experimental animals, and, in order to obtain larger quantities of the 

 extract for pathological research, biologists enlisted the help of the Hector 

 Whaling Company. During the 1955 season, P. T. Nowell managed to 

 collect large quantities of thymus extract on board the Balaena, and it is 

 hoped that in this way the causes of tnyasthenia gravis may be better 

 understood in the near future. 



M 



