YELLOW FEVER AND FISHES.^ 



By C. H. EIGENMANN. 

 (Read April 22, 1922.) 



If it were not for the little fishes, many parts of tropical America 

 would be uninhabitable. This is the excuse I have made, when an 

 excuse was necessary, for devoting all the time I could steal from my 

 family, my students, and my institution to gathering and contemplat- 

 ing the fishes of the rivers and lakes of South America. But pure 

 research no longer needs to apologize, because it has resulted in many 

 cases in unexpected, but lasting, benefits to man. 



I was trying to explain the evolution and distribution of the South 

 American fishes to a young manufacturer of veneer fruit boxes. 

 " You must excuse me," he replied, " but that seems like mighty 

 piddling business to me." I have sometimes been inclined to agree 

 with him. 



Yellow fever has been prevalent in Panama and Guayaquil, on 

 the coast of Ecuador, almost ever since the places were settled. The 

 French failed in building the Panama Canal on account of the fevers 

 that killed their men. The hospitals were full. It has been reported 

 that to keep ants from crawling up the bed-posts they were set in 

 dishes of water. Later it was found that mosquitoes bred in the 

 dishes of water, and that these mosquitoes carried the fever germs 

 from patients to well persons. The unrestricted breeding of mos- 

 quitoes made success impossible. 



General Gorgas cleaned out the mosquitoes in Cuba and in Pan- 

 ama. In doing so he not only made the Panama Canal possible, but 

 did far more in demonstrating that the worst pest-holes in the tropics 

 can be made habitable to man of the temperate zone. 



Guayaquil was perhaps the worst of all places in South America. 

 Yellow fever always existed and frequently there were outbreaks that 

 closed the port. 



1 Contribution from the Zoological Laboratory of Indiana University, No. 

 193. 



204 



