138 CONTEMPORARY SCIENCE 



it may well happen that suddenly through a fortunate 

 series of experiments or the opening- up of new methods, 

 a parasite hitherto regarded as invisible may be brought 

 into microscopic view. Should, for example, complete 

 evidence be brought forward to relate the Rickettsia bod- 

 ies to certain specific infectious diseases transmitted 

 especially by insects, as by the wood tick in Rocky Moun- 

 tain spotted fever, and lice in trench and typhus fever, 

 then another group will have been transferred from among 

 the ultramicroscopic to the visible parasites. A similar 

 situation exists regarding the globoid bodies of poliomye- 

 litis, the disease of man most convincingly established as 

 induced by a filterable microorganism. By means of a 

 highly specialized method of cultivation applicable espe- 

 cially to the class of spiral microbes, or spirochetae, Dr. 

 Noguchi and the speaker isolated from the nervous or- 

 gans of cases of poliomylitis, globular bodies so minute 

 as to be just at the limit of visibility under the highest 

 power of the microscope. With cultures of these bodies 

 they induced experimental poliomyelitis in the monkey; 

 but the culture method itself is so intricate that thus far 

 few bacteriologists have been able to repeat the work, 

 which, therefore, still awaits final confirmation. 



Since the recent pandemic of influenza and the assault 

 made upon the so-called influenza bacillus of Pfeiffer, 

 isolated first in Germany during the influenza epidemic 

 of 1889-1890, the inciting microbe of that disease has 

 been sought among the filterables. The announcement of 

 the finding of such a parasite in the nasopharyngeal se- 

 cretions by Nicolle and Lebailly of Paris in the autumn 

 of 1918, aroused high hopes which subsequent investiga- 

 tions have not served to sustain. The problem was ap- 

 proached in a somewhat different manner by two workers 

 Olitsky and Gates, at the Rockefeller Institute. Their 

 studies embraced two periods, the epidemics of 1918-1919 

 and 1920, and the intervening (interepidemic) period, 

 the latter serving as a control for the former. The es- 



