420 FAMILY: TRYPANOSOMIDyE 



had taken place within the cytoplasm of dead cells, just as it does in a culture 

 medium. The figures purporting to illustrate the development are not convincing, 

 and suggest the possibility of a mixed infection of leishmania and some other parasite, 

 such as a Sporozoon. 



Patton (1922) states that by a special technique he has confirmed Adie's 

 observations. He does not describe the technique, but, presumably, it is the culture 

 of leishmania in the bug's intestine after removal from the body. Neither Patton 

 nor Adie was able to obtain the intracellular development in living bugs. Because 

 multiplication takes place in dead or dying cells, it is not legitimate to conclude 

 that it will also occur in living ones. 



Cornwall and La Frenais (1922) repeated these experiments with living bugs. 

 They fixed the intestines entire and examined them in serial section, so as to retain 

 the normal relations of the cells. Though developmental forms of leishmania 

 occurred in the lumen of the intestine, sometimes in enormous numbers, there was 

 no indication of any intracelhdar development. 



The bodies which Adie (1922, 1922a) saw in the salivary glands of bugs, and 

 which were regarded as leishmania, have proved to be spores of a microsporidian. 

 Shortt and Swaminath (1924) have tested the infectivity of the developmental forms 

 of L. donovani in bed bugs Avhich had fed on a case of kala azar with parasites in 

 the jDeripheral blood. Nine days after feeding on the case the bugs were dissected, 

 and emulsion of their intestines injected intraperitoneally into mice. In the case 

 of one of these animals a culture was obtained from the spleen 123 days after the 

 injection. No parasites could be discovered in smears of the organs. Thus the 

 forms in the bugs on the ninth day were infective to mice, so that, as tliese intestinal 

 forms are presumably passed in the bug's dejecta, it is possible they might be 

 ingested or contaminate the puncture wound during or after feeding. Xicolle and 

 Anderson (1925) using over 2,000 bugs in Tunis failed to transmit L. donovani 

 from dog to dog, while Shortt and Swaminath (1925) were equally unsuccessful in 

 similar experiments with monkeys in India. 



Conorhinus mbrofasciatus. — Donovan (1909a) suggested this bug as a possible 

 vector of L. doyiovani, but no evidence of the development of the parasite in this bug 

 could be obtained by Patton (1912a). 



Fleas. — The occurrence of kala azar in dogs naturally turned the attention of 

 investigators to the possibility of fleas acting as transmitters. This view was first 

 exj^ressed by NicoUe (1908d), and was investigated by Basile in Italy (1910a, 1911, 

 1911a), who published the results of a series of observations by which he claimed 

 to prove that fleas were the true hosts of L. donovani. It has already been remarked 

 that at Bordouaro in Sicily, an endemic centre of the human disease, a high per- 

 centage of dogs was found to be infected. According to Basile, the only ectopara- 

 sites common to dog and man are the fleas Pulex irritans and Ctenoceplialus canis. 

 Attention has been drawn above to the fairly frequent association of infected human 

 beings and dogs in the same house. 



Basile' s investigations were conducted on two lines — namely, attempts at 

 infection of healthy dogs by fleas and the study of the leishmania in the flea. In the 

 first place (1911), he claimed that fleas which fed on spleen juice of cases of kala azar 

 became infected with cultural forms of leishmania, and that these produced infection 

 when injected into dogs. Three dogs were then said to have acquired the disease 

 by causing them to live with an mfected dog in Bordonaro. In another experiment 

 four dogs were infected in Rome by placing on them fleas taken from infected dogs 

 in Bordonaro. Experiments of this kind were rei>eated, and from what is now 

 known of the difficulties attending the inoculation of animals it is remarkable with 

 what apparent ease positive results were obtained. Sangiorgi (1911) relates that he 



