268 THE PROTOZOA 



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These parasites are grouped with the haemoflagellates and occur in their verte- 

 brate hosts exclusively as small, oval, cockle-shell-shaped bodies, measuring 2.5 

 3.0 microns. The protoplasm stains a faint blue and contains a rather large tropho- 

 nucleus which is peripherally placed and gives the appearance of the hinge of the 

 cockle shell. Besides this macronucleus we have a second chromatin staining body 

 which is often rod-shaped and set at a tangent to the larger nuclear structure. It is 

 called the blepharoplast or micronucleus and stains a more intense reddish than the 

 rather fainter stained pinkish macronucleus. One or more vacuoles are common in 

 the cytoplasm. 



Some consider these nonflagellated bodies, which are usually found packed in 

 endothelial cells of spleen, liver, lymphatic glands and bone marrow, as resting stages, 

 the flagellate existence occurring in some other host than its vertebrate one. Patton 

 has carried on an immense amount of experimental work with the bedbug and has 

 noted the development of flagellate forms from the fifth to the eighth days in bugs 

 which fed on kala-azar patients showing leishman bodies in their peripheral circula- 

 tion. If the bugs are allowed a second feeding after the infecting blood meal the 

 flagellates disappear within twelve hours, so that for full development in the bedbug a 

 single feeding is requisite. He states that the flagellate forms change to post-flagel- 

 lates ones by the twelfth day. At the same time, although much evidence exists in 

 favor of the bedbug as host for the flagellate forms, it has not been shown experi- 

 mentally that the bedbug is definitely connected with the transmission of the disease. 



Donovan is disposed to incriminate Conorrhinus rubrifasciatus as the transmitting 

 agent and furthermore he feels that there has not been sufficient investigation of mos- 

 quitoes along this line. 



In the regions where leishmaniasis of infants occurs there is also 

 found a similar disease of dogs and Basil e has claimed that the disease 

 is transmitted from dog to dog by the dog flea. 



As the dog has been regarded by some as the reservoir of the virus so naturally the 

 transmission of the disease from dog to child through the flea has been considered. 

 Wenyon, however, tried to infect two young dogs with great numbers of fleas which 

 had previously fed on dogs infected with canine leishmaniasis and at autopsy, five or 

 six weeks later, was unable to find parasites in smears from spleen, liver or bone 

 marrow and did not succeed in obtaining cultures from this material inoculated into 

 tubes of N. N. N. medium. 



As regards oriental sore Wenyon has found that bedbugs and Stegomyia will feed 

 from the sores and take up parasites which develop into flagellate forms in the gut of 

 the insects. 



Proof of transmission by these agents, however is lacking and others are inclined 

 to suspect the house fly or some species of moth midge. 



In Brazil there exists some evidence that the cutaneous leishmaniasis found there 

 may be transmitted by species of the tabanid family. 



It must be understood that there is always a suspicion that the 

 flagellate forms noted in arthropod experiments may be those of non- 

 pathogenic herpetomonad or crithidial species as such forms are 



