IMPLICATIONS 361 



Christiansen and Kernkamp isolated several species of Fusarium 

 from affected barley kernels, F. gramineimi being most common. 

 Extracts from pure cultures of these species did not prove toxic 

 to pigs, although they refused to eat barley that had been used 

 as a culture medium unless it was masked by mixture with a suffi- 

 cient quantity of other feed. When Christiansen and Kernkamp 

 inoculated wheat, barley, and corn with F. gram'meum at a time 

 when the grain was developing, the ripened kernels were found 

 to contain the toxic principle. Moreover, affected grain retained 

 its toxicity for long periods, at least 3 years. Affected kernels 

 tend to float at the surface of water; this fact can be utilized in 

 separating normal and scabby grains. 



Concerning the chemical nature of the toxic principle little has 

 been established to date, except that it is water-soluble and ther- 

 mostable. Schroeter and Strassberger (1931) found large quanti- 

 ties of choline and fatty acid esters of choline in Fusarium- 

 affected grain and expressed the opinion that these substances 

 constitute the toxic principle. 



It may be recalled that the proximate cause of wilting in vascu- 

 lar diseases of crop plants associated with species of Fusarium is 

 commonly regarded as a toxin. The experiments with Fusarium- 

 affected grain indicate, as a line of departure, the employment of 

 animals in studies involving the nature of such toxins in Fusaria 

 causing vascular-wilt diseases. 



IMPLICATIONS 



In the past, studies of poisonous fungi have been concerned 

 mainly with the identity of the poisonous fungus, with the na- 

 ture of its toxic principle, and with the effects of this principle 

 upon animals and man. Too little is yet known about fungi 

 poisonous to seed plants. It is indicated that future studies should 

 stress plant toxemias to a greater extent than have those of the 

 past, in order to account for the disease syndrome. By the use 

 of plant toxins as antigens, it should be possible to produce specific 

 antitoxins. Furthermore the ultracentrifuge and electron micro- 

 scope should enable the worker to purify fungus toxins and anti- 

 toxins and thus to learn something more of their physical prop- 

 erties and eventually of their chemical constitution. 



