MOSQUITOES AND FLEAS. 31 



Europe), Ryama striata (striped hyena), Leptis timidus (common hare), 

 and Procyon lotor (raccoon). It is also said to occasionally sip human 

 blood [sic!]. I have specimens from various parts of North America, 

 and also from Europe." Many unfortunate inhabitants of New York, 

 Philadelphia, Washington, and Baltimore during the past few summers 

 will be able to verify Mr. Baker's statement that the species occasion- 

 ally sips human blood! This species may be distinguished at a glance 

 from the so called human flea {Pulex irritans) by the fact that the latter 

 species does not possess the strong recurved spines on the margin of 

 the head, which show so distinctly in tig. 5. 



ADDENDUM. 



The so-called permanganate of potash remedy against mosf/uitoes. — 

 During 1898 a newspaper article, purporting to be copied from the 

 Public Health Journal, was widely published throughout the country. 

 It claimed that a handful of permanganate of potash will oxidize a 

 10-acre swamp, kill its embryo insects, and keep it free from organic 

 matter for thirty days, at a cost of 25 cents, and that the insect in all 

 of its stages can be instantly killed by contact with minute quantities 

 of the substance. 



The article showed great ignorance in the life history of the mosquito, 

 but it gained such wide credence that experiments were undertaken by 

 the writer. It was found that small quantities of the chemical had no 

 effect whatever on the larvae, which were, however, killed by using 

 amounts so large that, instead of using "a handful to a 10-acre swamp," 

 at least a wagon load would have to be used to accomplish any result. 

 Moreover, after the use of this large amount and after the larva^ were 

 killed, the same water twenty-four hours later sustained freshly hatched 

 mosquito larvte perfectly, so that even were a person to go to the pro- 

 hibitive expense of killing mosquito larva' in a swamp with perman- 

 ganate of iDotash, the same task would have to be done over again two 

 days later. 



