68 



JOURNAL OP ECONOMIC ENTOMOLOGY 



[Vol. 1 



The exact position of some of the spirochaetae is in question at 

 present but they are believed to belong to the MastigopJwra. 



It seems probable that blood parasites exist in certain hosts without 

 ill effect, such animals being naturally immune or having acquired 

 immunity. When these organisms are transmitted to the blood of 

 susceptible hosts, however, as are the various species of Piroplasma, a 

 disease of more or less severity results. This is the case with the try- 

 panosome of tsetse-fly disease, which Koch has found to be transmitted 

 from the crocodile to man by the tsetse-fly {Glossina spp.). Again, 

 while the organism producing Rocky Mountain spotted fever has not 

 been discovered, yet Dr. H. T. Ricketts^^ has produced the disease in 

 guinea pigs by ticks from horses, cows and vegetation and suspects 

 its transmission from the blood of some animal which has served as 

 host. 



TABLE SHOWING THE ZOOLOGICAL POSITION OF THE TICK TRANSMITTED 

 PARASITES, PIROPLASMA SPP. 



PROTOZOA. 



Class (1) Rhizopoda 



(Sarcodina) 



Class (2) Mastigophora Class (3) Sporozoa 

 Probably includes the 

 Spirochaetae transmit- 

 ted by the Ar^asid ticks 

 as well as the Trypan- 

 osomes transmitted by 

 flies of genua Olosaina 



Class (4) Infusoria 



Sub Class Telosporidia 



Sub Class Neosporidia 



Order (l) Gregarinoidea 



Order (2) Haemoaporidia 



Order (3) Coccidiidea 



(1) Plasmodium 



( Haemamoeba ) 

 Including the mal- 

 arial parasites trans- 

 mitted by mosqui- 

 toes, of the genus 

 Anopheles 



(2) Haemogregarina 



(3) Piroplasma 



P. bigeminum 

 P. parvum 

 P. ovis 

 P. equi 

 P. cants 



etc. 

 Transmitted by the 

 Izodinid ticks 



(4) Halteridium (?) 



