296 SANITARY ENTOMOLOGY 



insect are so minute that they have not yet been demonstrated. The 

 organism Spiroschaudinnia herhera Sergent and Foley is considered as a 

 biological species, not morphologically separable from S. reciirrentis. 



Spiroschaudinnia recurrentis (Lebert) causes EUROPEAN RE- 

 LAPSING FEVER. Although many authors consider the above men- 

 tioned relapsing fevers as identical with the European fever, the evidence 

 of louse transmission was slow in coming. Manteufcl (1907) found that 

 the rat louse, Polyplax spinulosus, mny carry the disease from rat to 

 rat, and suggested that possibly Pediculus corporis could carry it to 

 man. Other authors made similar suggestions. Finally Toyada (1914) 

 found crushed lice infective for mice up to three days after they had fed 

 on infective blood. Since the outbreak of the great war the conviction 

 of the role of the louse as a vector of European relapsing fever has be- 

 come very strong. In fact repressive measures used in Roumania against 

 the louse were effective against the fever. This disease can also be car- 

 ried by the bedbug, Cimex lectidarius. 



Spiroschaudinnia duttoni (Novy and Knapp) causes RELAPSING 

 FEVER OF TROPICAL AFRICA which normally is transmitted to man 

 by the tick Ornithodoros moubata, but Neumann (1909) found that it 

 could occasionally be transmitted from rat to rat by means of the rat 

 louse, Polyplax spinulosus. 



Spiroschaudinma sp., cause of MANCHURIAN RELAPSING 

 FEVER, is claimed by Toyada (1917) to be transmitted by lice. 



Leptospira icterohemorrhagiae (Inada and Ido) causes INFEC- 

 TIVE OR EPIDEMIC JAUNDICE, also known as Weil's disease which 

 is infective to man and rats. In the European trenches the rat is re- 

 garded as the reservoir of the disease. The spirochaete is excreted by 

 way of the urine or feces of rats or men and is consequently easily com- 

 municated through the trenches. It is readily communicated through 

 the mouth or through abrasions in the skin (Dawson, Hume and Bed- 

 son, 1917). Stokes conducted negative experiments with Pediculus cor- 

 poris, but these experiments were not directed toward obtaining infec- 

 tion through crushing or scratching lice or feces into abrasions of the 

 skin. This phase of the subject will bear further investigation especially 

 since Dietrich (1917) declares that the disease can be carried by 

 Pediculus corporis. 



Telosporidia: Haemogregarinida: Haemogregarinidae 



Haemogregarina (Hepatozoon) gerbilli (Christophers) cause of the 

 ANEMIA OF THE JERBOA, Gerbillus indicus in India, is believed 

 by Christophers (1905) to pass its cycle of sporogony in the rat louse 

 Polyplax stephensi C. and N. 



