510 ANNUAL REPOBT SMITHSONIAN INSTITUTION, 1917. 



tan species in Denmark have been proven to act as secondary host to 

 a bacillus which produces cancer in rats.^ Morrell concludes that the 

 common croton bug, by contamination with its feces, is able to, and 

 may possibly, play a small part in the dissemination of tuberculosis 

 and in the transmission of pologenic organisms,^ also that they are 

 in all probabilities an active agent in the souring of milk kept in 

 kitchens and that they are undoubtedly a very important factor in 

 the distribution of molds to foods, etc., in cupboards and cellars. 

 Gates states that roaches may spread typhoid on ships and carry in 

 their intestines and on their feet the organisms of diphtheria, tonsil- 

 itis, and tuberculosis,^ and some writers consider them fully as dan- 

 gerous as house flies, as the virility of bacterial organisms is not 

 diminished by passing through their alimentary tract.* A Danish 

 professor claims that cancer is caused by drinking water in which 

 cockroaches have oviposited ^ and roaches have been mentioned as 

 possible transmitters of the tropical disease beri-beri.** Eoaches have 

 also been considered in connection with the carrying of the %abrios of 

 Asiatic cholera,^ and, in common with many other insects, they have 

 been investigated as possible factors in the cause and spread of pel- 

 lagra, but with negative results.* 



There are few published references of Orthoptera, other than the 

 roaches, as disease carriers, the only one now recalled being the 

 spread of cholera for long distances by migratory locusts in Africa.^ 

 It is recorded that grasshoppers in times of invasions leave a cholera- 

 like pestilence in their wake and they are also accused of carrjdng 

 into uninfested regions the foot-and-mouth disease of cattle.^" 



Aside from physical effects, either external or internal as discussed 

 above, man is injuriously affected directly by orthopterous insects 

 scarcely at all. Aside from disagreeable odors of such species as 

 cockroaches, etc., that offend his olfactory sense, his psychic nature 

 is practically unaffected. 



Orthoptera beneficially related to man directl}' may be divided, 

 like those injuriously affecting him, into those affecting him physi- 

 cally and those influencing him psychically. The first group com- 

 prises species used in medicine and those eaten as food. The former, I 



iFibiger, Berliner Kiln. Wochenschr., vol. 1, p. 289-298 (1913), FIblger Hospitalstid, 

 Copenhagen, vol. 57, p. 1049-1112 (1914), and Fibiger and Dltlevsen, Contr. bid. morph. 

 Splroptera (1914). 



2 British Med. Journ., p. 1531 (1911). 



su. S. Naval Med. Bull., vol. 6, p. 212 (1912). 



< Longfellow, Amer. Journ. Pub. Health, vol. 3, p. 58-61 (1913). 



"Nordlyset, New York, Feb. 20, p. 8 (1913). 



«Van der Scheer, Journ. Trop. Med., vol. 3, p. 96-97 (1900); Manson, Tropical 

 Diseases (4 ed.), p. 376 (1907). 



•f Barber, Philippine Journ. Scl., vol. 9, p. 1-4 (1914). 



« Jennings, Amer. Journ. Med. Sci., vol. 146, p. 418 (1913). 



» Riley, Ref. Handb. Med. Sci., vol. 5, p. 75 (1887). 



" Kannemeyer, Trans. S. Afr. Phllos. Soc, vol. 8, p. 84-85 (1893). 



