THRUSH. 639 



At present, little is known concerning immu- 

 nity to these infections. Ricketts prepared a vac- 

 cine by disintegrating the organisms in a ball- 

 mill, and in collaboration with Eggers found that 

 the immunization of animals with the vaccine 

 causes the formation of agglutinating or precipi- 

 tating antibodies (from unpublished experiments). 

 The practical value of the vaccine has not had a 

 thorough trial. Christensen and Hektoen used 

 it in two cases of systemic blastomycosis which, 

 however, were so far advanced that no conclusions 

 as to the value of the treatment could be drawn. 

 Theoretically, the conditions would seem to be 

 favorable for the vaccine treatment of blastomy- 

 cosis, since the disease is of a chronic character 

 and there is little opportunity for autoimmuniza- 

 tion on account of the dense capsule which sur- 

 rounds the organisms. By grinding the organ- 

 isms up, their constituents may be injected in 

 such condition that they are readily absorbed. 



Thrush. 



Ophiils very properly suggests that thrush 

 should be considered as one form of oidiomycosis. 

 Thrush is of particular interest because of the early 

 date at which its parasitic nature was recognized. 

 Langenbeck and Berg, in 1839 and 1841, are cited 

 as the discoverers of the fungus, and they repro- 

 duced the disease by inoculations with fragments 

 of the membrane. The parasite was studied a little 

 later by Gruby, Robin and others, and the latter 

 gave it the name of Oidium albicans. Grawitz ob- 

 tained it in pure culture in 1877 and demonstrated 

 its pathogenicity for dogs and rabbits. 



