38 (20S) SOCIETY FOR EXPERIMENTAL BlOLOGY AND MEDICINE. 



apparent. Their margin is somewhat raised above the surface of 

 the intima, their center somewhat depressed. The more numerous 

 the injections the more pronounced and extensive the alterations ap- 

 pear, but they are always of the same character. The authors have 

 not yet concluded their experiments and they have not yet been able 

 to carry the number of injections beyond 50. The lesions here 

 described have nothing in common with human arteriosclerosis. 

 They are in every essential identical with what B. Fischer describes 

 as the result of adrenalin and digalen injections. It can be demon- 

 strated that the primary lesion takes place in the muscle cells of 

 the media and first of all in those nearest to the intima. Here 

 the nuclei become broken up, the chromatin is scattered, the entire 

 cell becomes necrotic and is finally destroyed. This process gradu- 

 ally extends downward in the direction of the adventitia. As the 

 muscle cells disappear, the elastic fibers, under pressure of the 

 blood-current, are first stretched, then broken up. The entire 

 wall of the vessel in this spot is thus attenuated and distended and 

 finally calcified. There is distinct arterial necrosis. Thus far the 

 authors have been able to find these lesions only in the aorta. 

 The fact that they are found mainly in the aorta, that they occur 

 in patches, that they begin with necrosis of the muscle cells and 

 that thus far only adrenalin, digalen and nicotin, all three vaso- 

 constrictors, have been found to produce them, would suggest an 

 affection of the vasovasorum as the underlying cause. This, how- 

 ever, is not yet proved. 



In all advanced cases the left heart has been found hypertro- 

 phied. Certain minute lesions have been found in the heart 

 muscle. The kidneys have thus far only shown a moderate degree 

 of hyperemia. An occasional trace of albumin appeared in the 

 urine but never any sugar. In every case that has received a 

 sufficient number of injections very definite changes are noted in 

 the liver. The liver cells appear entirely normal, as do also the 

 central vein and the interlobular vessels, but the interlobular bile 

 ducts, even at a very early period, are found surrounded by a 

 mantle of leucocytes which increases in size after the injections 

 are continued. The leucocytes not only surround the ducts but are 

 found within the walls and even in the interior of the duct overly- 

 ing the epithelium. This latter is always perfectly normal and the 



