128 Function and Regeneration of Preci2)itins 



during pregnancy. This observation was subsequently confirmed by 

 Moro (31, X. 1901) Avith lactosera, and Biondi (1902, p. 15) with 

 haematosera. 



The function of the precipitins in corpore is not as yet cleared up. 

 Presumably they serve to protect the body against the injurious effects 

 of corresponding foreign albumins, and more probably, as is suggested 

 by Michaelis and Oppenheimer (1902, p. 363) to neutralize the 

 specifically foreign character of the albumin introduced, thereby making 

 it forthwith assimilable. This may explain the physiological signifi- 

 cance of the phenomenon, and I might add, is in substantial agreement 

 with Ehrlich's theory as to the function of antibodies in general. 



The regeneration of precipitins in the body after large bleedings 

 would appear improbable from the investigations of Rostoski. It will 

 be remembered that a regeneration of diphtheria antitoxin has been 

 observed in animals subjected to large and repeated bleedings (see 

 p. 10). Rostoski (1902, b. p. 35), in a similar manner, subjected his 

 rabbits to one large bleeding (drawing 55 to 64 c.c. from animals 

 weighing 2000 to 2300 g.), and tested their serum for precijDitins nine days 

 or so later. He observed a marked decrease in the precipitins and con- 

 cludes that they are not regenerated. It appears to me that these 

 experiments should be repeated with the aid of my quantitative method. 

 Rostoski notes, however, that the relatively rapid disappearance of 

 precipitins from the bloods, after treatment has ceased, indicates that 

 precipitin production soon ceases, owing possibly to the elimination of 

 the foreign substance which has stimulated their production. He 

 nevertheless considers it possible that the anaemia following large 

 bleedings may also affect the activity of the sources of precipitin 

 formation. 



The systemic reaction of treated animals is slight, if we except the 

 slight loss of weight which follows the first injections in properly treated 

 animals, by which I understand animals treated with graded doses 

 which do not injure or destroy them by intoxication. It is easy to 

 observe that a leucocytosis follows the injection of foreign substance, 

 which is usually most marked in immune animals (note immunity to 

 bacteria). As stated by Michaelis and Oppenheimer (1902, p. 356), 

 rabbits treated by intraperitoneal injection of serum (they used ox 

 serum) develope a leucocytosis due to multi-nuclear granular, and 

 mono-nuclear non-granular leucocytes. On examining the peritoneum of 

 animals receiving an injection of serum for the first time, nothing 

 abnormal is observed after absorption has taken place. On the other 



