144 CONTEMPORARY SCIENCE 



in order to increase or otherwise modify the infective 

 material withdrawn from the blood. 



The discovery of the yellow fever spiral definitely re- 

 moves the disease from the class believed to be provoked 

 by ultramicroscopic organisms, and at the same time adds 

 so well defined a microbe as Leptospira icteroides to the 

 group of filter passers. The data so far secured regard- 

 ing this spiral in relation to yellow fever fulfill the con- 

 ditions arising out of Reed and Carroll's discoveries in 

 connection with the disease in man. These are great gains 

 for theoretical bacteriology. The rewards to practical 

 medicine are even greater, since it has been found that 

 Leptospira icteroides lends itself to the making of an 

 active vaccine (killed organisms) and also an effective 

 therapeutic serum. Hereafter yellow fever is to be com- 

 bated (i) by removing the breeding places of the stego- 

 myia, (2) through vaccination, and (3) by an antiserum. 



The etiology, or causation, of yellow fever so long and 

 fruitlessly sought seems to have been solved, and it may 

 be of interest to inquire why just at this juncture? The 

 answer is, through the conjunction of the "prepared mind" 

 and animal experimentation. For nearly a decade No- 

 guchi has been investigating this spiral class of microbes, 

 in course of which he added materially to our knowledge 

 of methods of study and of new species. He had first- 

 hand knowledge of a related disease, infectious jaundice, 

 transmissible to guinea pigs, which prevails endemically 

 in Japan and sporadically elsewhere, and in which Inada 

 had discovered a peculiar spiral organism (Spirocheta 

 ichterohccmorrhagice) . In other words, the time was ripe 

 and Noguchi peculiarly equipped to take up again and in- 

 vestigate with newer methods the problem of yellow 

 fever. 



The story is still incomplete, as recent developments 

 have shown ; for just as Metchnikoff and Bordet had seen 

 the pallida before Schaudinn, so it now appears Stimson 

 of the U. S. Public Health Service had previously ob- 



