ANTIFERMENTS 259 



After he had proved experimentally that the animal organism is able 

 to mobilize ferments against foreign substances, Abderhalden next 

 took up the question whether ferments are produced when substances 

 native to the body but foreign to the blood are introduced into the cir- 

 culation. Having learned from the researches of Veit, Schmorl, Weichard, 

 and others that during pregnancy syncytial cells frequently enter the 

 maternal circulation, Abderhalden used the serums of pregnant animals, 

 and found that they contained a ferment-like substance capable of 

 splitting placental peptone into amino-acids and coagulated placenta 

 into peptones, polypeptids, and amino-acids. 



It was apparently thus established that the body cells are harmonic- 

 ally attuned to one another, and if new or modified cells or their prod- 

 ucts are brought into relation with other cells, they are received as 

 foreign invaders, and their entrance is followed by the production of 

 what Abderhalden has called "protective ferments" ("Abwehrfermente") 

 capable of bringing about their cleavage into simpler products. In this 

 manner the presence in the circulation of some of the body cells may 

 give rise to the production of these ferments if the cells in question are 

 really foreign to the blood-plasma and other cells. 



Abderhalden has also stated that although he was led to make 

 these investigations on the supposition that syncytial elements were 

 present in the blood of pregnant women, it is not necessary that they be 

 constantly in the blood, for every case of pregnancy has a complicated 

 protein metabolism and there is a general exchange of substances between 

 the placenta and the maternal blood that permits the entrance into the 

 latter of protein products that have not been broken down completely 

 into amino-acids, and that cause the organism to produce defensive 

 proteolytic ferments. 



In cancer, where the production of new cells is so marked, some of 

 these cells or their products may easily be swept into the general circula- 

 tion, where they act as foreign invaders and cause the formation of pro- 

 tective proteolytic ferments. It is a noteworthy fact, moreover, that 

 the serum of carcinoma cases reacts best with carcinoma cells and that 

 of sarcoma with sarcoma cells. 



Similar ferments have been described in other conditions. Fauser 

 has demonstrated that the blood-serum of dementia prsecox patients 

 contains ferments that act on the reproduction glands, so that the serum 

 of males reacts with testicular extracts and that of females with ovarian 

 extracts. These serums were, however, also found to react with thyroid 



