OF WASHINGTON, VOLUME XVIII, 1916 87 



results from mechanical irritation by particles contained in such 

 polluted water. 15 



However few or doubtful the records of Orthoptera directly 

 causing disease in mankind, their instrumentality in the dissemi- 

 nation of disease organisms is a matter well worth consideration. 

 Their importance in this respect is, of course, slight as compared 

 with some other groups, especially the Diptera, and this phase 

 of the subject is insignificant as compared with the general 

 subject of medical entomology. But that certain Orthoptera, 

 especially the Blatticlae, may yet prove of real importance as dis- 

 seminators of disease is not to be doubted. That they are well 

 qualified for playing such parts is certain. Many published 

 articles show cockroaches to be veritable hotbeds of various kinds 

 of germs and that they fairly teem with bacterial organisms both 

 inside and out. 16 Their eggs are covered with bacteria when de- 

 posited 17 and their feces show micrococci in abundance. 18 They 

 may carry the hypopus stage of the cheese mite 19 and common 

 cosmopolitan species in Denmark have been proven to act as 

 secondary host to a bacillus which produces cancer in rats. 20 

 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 polo- 

 genie organisms, 21 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, tonsillitis and tuberculosis, 22 

 and some writers consider them fully as dangerous as houseflies 

 as the virility of bacterial organisms is not diminished by passing 

 through their alimentary tract. 23 A Danish professor claims that 

 cancer is caused by drinking water in which cockroaches have ovi- 

 posited 24 and roaches have been mentioned as possible transmit- 



I5 Prout, Journ. Trop. Med. and Hygiene, p. 137-139 (1908). 



16 Herms and Nelson, Amer. Journ. Pub. Health, vol. iii, p. 229 C1913), 

 Sartpry and Clerc, C. R. Soc. Biol., vol. Ixiv, p. 545 (1908), and Barber, 

 Philippine Journ. Sci., vol. vii, p. 521-524 (1912). 



17 Petri, Mem. d. R. Stazionc di Palol. Vegetale, Rome (1909). 

 > Northrup, Tech. Bull. Mich. Kxp. Stat., No. 18, p. 25 H914). 



19 Ealand, Ins. and Man, p. 244 (1915). 



20 Fibigcr, Berliner Klin. Wochcnschr., vol. 1, p. 2S9-298 (l'Jl3), Fibige ' 

 Hospitalstid, Copenhagen, vol. Ivii, p. 1049-1112 (1914), and Fibiger ar 

 Ditlevsen, Contr. liiol. morph. Spirnplera (1914). 



21 British Med. Journ., p. 1531 '1911). 



2 U. S. Naval Med. Bull., vol. vi. p. 212 C1912). 



:s Longfellow, Amer. Journ. Pub. Health, vol. iii, p. 58-61 (1913). 



24 Nordlyset, New York, Febr. 20, p. 8 (1913). 



