330 IMMUNOLOGICAL METHODS OF DIAGNOSIS 



rule. This divergence in results is no doubt due in part to the fact 

 that the technical difficulties which are involved in the investiga- 

 tion of deviations in the function of certain tissues are greater with 

 some than with others, and I must confess that in many cases I 

 am more inclined to attach significance to negative than to positive 

 reactions. The reason why the most satisfactory results on the 

 whole have been obtained with placental and testicular tissue is 

 no doubt owing to the fact that these tissues can be prepared free 

 from blood and substances which react by themselves with nin- 

 hydrin, more readily than others. A hyperplastic thyroid with 

 but little colloid formation is an ideal tissue to work with, and 

 unquestionably gives specific reactions, while a specimen which is 

 relatively rich in colloid gives blue reactions in such an overwhelm- 

 ingly large number of cases that no one would seriously consider 

 them as specific. As regards tumor antigens I have one tissue in 

 my possession at the present time which will give an apparently 

 specific reaction (as judged by the usual controls) with any normal 

 serum even, while another has not yet reacted with a single case 

 of cancer! 



Evidently the path of the laboratory worker along these lines 

 is not strewn with roses. 



Aside from the diagnostic interest which attaches to the discovery 

 of the antitissue ferments it is interesting to note that studies in 

 this direction have also furnished additional evidence regarding the 

 remarkable interrelation between the various organs of the body 

 and especially of the ductless glands. It has thus been shown 

 that in mental disturbances in connection with a Basedow thyroid, 

 where ferments against this tissue, as well as cortex and sex gland 

 could be demonstrated in the blood, resection of the gland was fol- 

 lowed (aside from clinical improvement) not only by a disappear- 

 ance of the anti-Basedow ferments, but also of those directed against 

 cortex and sex gland. Evidently an opportunity for work has 

 here been opened which promises results of definite value in one of 

 our saddest and darkest fields of medicine. 



ALLERGIC REACTIONS. 



By the term allergic reaction in the clinical sense we understand 

 the specific symptomatic response on the part of the infected and 



