218 IMMUNOLOGY 



Behavior of Cells, — By means of this technique they investi- 

 gated first the behavior of red cells before and after they had 

 adsorbed hemagglutinin. Before adsorption they readily passed 

 from the aqueous phase into the oil phase indicating that their sur- 

 faces Avere richly endowed with material readily miscible with oil. 

 Referring to Harkins' work (see Fig. 26) (Appendix, p. 000) this 

 would be interpreted as indicating that the nonpolar groups of the 

 molecules were out. 



Change in Surface Molecular Orientation. — After adsorp- 

 tion of agglutinin the surface appeared to contain predominantly 

 polar groups, since the cells were no longer miscible with oil but 

 were readily miscible wnth the aqueous phase (Ringer's solution). 

 Using the same technique they also studied acid-fast bacteria and 

 observed the same phenomenon. Both Freund and ]\Iudd and Mudd 

 regard the surface of the unsensitized acid-fast bacteria as con- 

 taining both protein and lipoid. From their work they conclude 

 that the acquisition of polar groups results from adsorbed antibody 

 globulin. This specific adsor])tion of antibody globulin constitutes 

 the first phase of Bordet's hypothesis. 



Antigenic Components and Antibodies. — In Chapters XI and 

 XIX the various possible antigenic components of the bacterial 

 cell were discussed. The student should bear in mind that accord- 

 ing to present concepts as many different antibodies may be pro- 

 duced as a result of infection or immunization as there are true 

 antigenic components or hapten-protein combinations. 



In the case of motile bacteria there are flagellar (H) as well as 

 somatic (0) antigens. The rough colony type of bacteria con- 

 lain antigens (protein) which stimulate the production of cor- 

 responding antibodies and the smooth colony types contain carbo- 

 liydrate-protein complexes that stimulate antibodies that react 

 citlier M'ith the combination or with the hapten portion in vitro. 

 The latter, however, is frequently not a true antigen by itself. 



Nonprotein Carriers of Haptens. — Recently Zozaya (1932) has 

 Referring to Harkins' work (see Fig. 26) (Appendix) this would 

 be interpreted as indicating that the nonpolar groups of tlie 

 He considers that the physical attachment of the hapten to a col- 

 loid makes it an antigen. This revolutionary concept is in line 

 with Zinsser's suggestion that antibody formation is largely a 

 cell surface phenomenon and depends among other things upon 



