30 



Araehnida and Myriopoda 



a parasite of the black rat (Rattus rutins), is also widely distributed 

 in the East. These species of Dermanyssus found on rodents have 

 only recently been discovered, and are not yet known to bite 

 human beings, but the possibility of their doing so should be 

 borne in mind. 



Bird-mites (presumably D. gallinac) have been proved by 

 Mayer to transmit spirochaetosis (Spirochaeta gattinarum) in 

 canaries, but it is not certain whether infection is due to the 

 bites of the Acari or to their being swallowed by the birds. 



Andrew Balfour found blood-parasites (Haemogregarina jaculi) 

 in blood from the alimentary canal of mites of the genus 



Fig. 13. 



Dermanyssus aegypiius, Hirst. Sketch of 

 the front end of the body of the 

 female, showing the mandibles in situ. 

 Greatly enlarged. 



Dermanyssus occurring on jerboas at Khartoum. He suggests 

 that the mite may be found to serve as an intermediate host for 

 this blood-parasite. Dr. Balfour thought that the mite in question 

 was D. gallinac, but it is more likely to be one of the species 

 peculiar to rodents. 



Another species of fowl-mite (Liponyssus bursa, Berlese) occurs 

 in many tropical countries, and has been discovered on human 

 beings at Zanzibar. A specimen of this fowl-mite was found by 

 Dr. H. L. Howell, B.A.M.C., at Ahmednagar, Deccan, India, on a 

 lady suffering from " very bad irritation of the skin " alleged to be 

 caused by the mite. " It raised small red lumps with white tops, 



