354 UUEUIGER. 



oT iuniuals wliic-li had Ih'ch Irealcd with diphtheria antitoxin or with 

 tvphoid agglutinating serum did not possess any substances which neutral- 

 ized or prevented the action of tlie respective antitoxin or agglutinin. 

 On the other hand, tlie serum of animals which had been treated with 

 lactoserum^ when mixed with hK'tosei-uin |)i('veiited the action of the 

 hitter upon milk. 'Die authors conclude: 



I. IiiumiMc siilistances, as diplitlieria antito.xin and typlioid agglutinin, can not 

 Icail to tlu' production of antibodies wlien injected into an animal. 

 IJ. Treating an animal with lactoserum produces antilactoserum. 



It must be home in mind that practically all of our ideas concerning 

 the production of antibodies are based upon expei-imental work relating 

 to bacterial diseases and that the nature of the causative agent of cattle 

 plague is as yet entirely unknown. It is therefore possible that the 

 protective substances of anticattle plague serum are radically different 

 from the antibodies with which we are acquainted and have a different 

 mode of action. According to current notions, it is theoretically impos- 

 sible to obtain antibodies by injecting an antiserum obtained from one 

 animal into another animal of the same species. Nevertheless, cattle 

 w^ere used in these experiments both for the production of the anticattle- ' 

 plague serum and in the attempt to obtain a serum antagonistic to the 

 anticattle-plague serum. This plan was pursued primarily as has been 

 intimated because of the imminently practical question as to whether or 

 not overimmunization could lead to the production of susceptibility to 

 the disease. However, it was also desirable to observe whether the Jaws 

 of immunity involved were the same for cattle plague as they wei'e for 

 bacterial infections. 



The following experiments were performed to show whether or not 

 substances which render inert anticattle-plague serum are produced when 

 the latter is injected at intervals into cattle. 



EXPERIMENTAL. 



Nine bullocks, non-immune to cattle plague, numbei'ed IG, 17, 1<S, lij, 

 20, 22, 23, 24, and 25 were used. 



Bullocks Nos. 10, 17, 18, 19 and 20 lemained untreated ; Nos. 22, 23, 

 24 and 25 received three injections of 100 cubic centimeters each of 

 anticattle-plague serum at intervals of ten days. On the 28th day of 

 June, these bullocks were subjected to the simultaneous method of im- 

 munization, Imllock No. 16 acting as control. 



Bullock Xo. 1() i-eceived 0.5 cubic centimeter of virulent blood under 

 the skin and died of cattle plague within eleven days after inoculation. 

 (Chart No. Ki.) 



I>ul!i)ck .\o. 17 received 0.5 cubic centimetei' of virulent Ijlood, and 

 50 cubic centimeters of anticattle-plague serum per 100 kilos weight and 

 died of cattle plague within eleven days after inoculation. (Ohart No. 

 17.) 



