648 



SCIENCE 



[N. S. Vol. XXVII. No. 695 



I believe that lytic immunization will 

 prove in the near future of great service 

 not only in aifording protection, but in the 

 treatment of some infectious diseases, yet 

 it will be well to understand at the outset 

 that it vsdll have its limitations and also its 

 dangers. We can not hope for the high 

 degree of protection that is secured by the 

 antitoxic treatment of diphtheria. From 

 my experiments upon animals with the 

 haptophores of the colon and typhoid ba- 

 cilli I believe that an immunity to from 

 ten to twelve times the minimum fatal 

 quantity of the living bacillus is as much 

 as we can reasonably hope. 

 The Differentiation of Homologous Pro- 

 teins hy Serum Reactions: S. P. Beebe. 

 It is now admitted by all laboratory 

 workers in the field of immunity that one 

 can differentiate between the proteids of 

 different species of animals by means of 

 serum reactions. Such reactions are not 

 absolutely specific, as it is well known that 

 closely related species of animals show a 

 mild reaction, but in point of time and 

 completeness of the reaction it is possible 

 to differentiate sharply between species. 



With homologous proteids there is no 

 such unanimity of opinion, although com- 

 paratively little work has been done. The 

 serum reactions are capable of showing 

 differences in structure which we can not 

 demonstrate by other means, and it seems 

 reasonable to believe that we may be able 

 to differentiate between proteids from the 

 same species, but from organs having wide- 

 ly varying functions, such as the liver and 

 the kidney. For the purpose of developing 

 the anti-serum the nucleoproteids of these 

 organs have been injected into alien spe- 

 cies of animals. The nucleoproteids were 

 chosen because they are readily prepared 

 and because they probably represent the 

 most important of the cell constituents. 

 By means of such serum one may obtain 

 precipitin and agglutinin reactions, which 



are specific in the same sense that heterol- 

 ogous reactions are specific. 

 On Spirochetal Immunity: F. G. Novr and 



R. E. Knapp. 



The question of the plurality of species 

 of spirilla in relapsing fever, raised by us 

 two years ago, has been answered since in 

 the affirmative, for we now have four, and 

 possibly five, essentially distinct strains in 

 human relapsing fever. These several spe- 

 cies, strains or varieties are: 



S. Obermeieri — origin, Moscow, Uhlenhuth and 

 Haendel. 



8. Novyi — origin, New York, Norrls. 



8. Kochi n. sp. — origin, East Africa, Berlin, 

 Koch. 



8. Duttoni — origin. West Africa, Runcorn, But- 

 ton and Todd. 



8. Carteri — origin, Bombay. 



The specific differences for the first four 

 have been fully established and it is quite 

 certain that when direct comparative tests 

 are made with the Bombay spirillum this 

 will also be found to be distinct. In view 

 of these facts it may well be asked whether 

 a still greater number of strains will not 

 be found when further comparisons are 

 made with the spirilla from different parts 

 of Russia, Africa, Asia and America. 

 From our studies on the immunity reac- 

 tions of the first four spirilla we are in- 

 clined to believe that such will be the case 

 and that a considerable number of appar- 

 ently different species or strains will be 

 discovered. The necessity for recognizing 

 this condition of affairs will be apparent, 

 for, as will be shown, the curative action 

 of the serum of an animal immunized to 

 one strain is manifested only in animals 

 infected with that particular organism and 

 is without appreciable effect upon the other 

 strains. 



The four strains in the order as listed 

 above show a marked gradation of proper- 

 ties. This is seen in the duration and 

 severity of the initial attack, in the fre- 

 quency and intensity of relapses and in the 



