INOCULATION OF INVERTEBRATES FROM INSECTS 395 



an infection noted. Yamasaki (1924) also failed to infect mice and dogs with 

 L. ctenocephali. 



Becker (1923a), using C. gerridis, H. muscarum, and the flagellates of the sheep 

 ked, failed entirely to produce infection in seventeen rats, three mice, one rabbit, and 

 one guinea-pig. As in the case of Iloare's and Shortt's experiments, cultures on 

 X.N.X. medium were attempted. Strong (1924) likewise failed to infect animals 

 with the flagellates of the bugs found on Euphorbias, while Drbohlav (1925) failed 

 to produce any infection with L. ctenocephali in about 150 animals examined by 

 the smear and culture method after inoculation. 



There is no longer any doubt that the C. melophagia of the sheep ked is in reality 

 T. melophagium of the sheep, yet, by inoculation of this trypanosome to mice, 

 Laveran and Franchini claim to have obtained infections of the leishmauia type. 

 As pointed out by Hoare (1921a), if an infection had occurred, it would almost 

 certainly have been of the ordinary trypanosome type. Buchner (1922), who also 

 faUed to infect mice with the ked flagellate, likewise points out this fallacy in the 

 experiments of Laveran and Franchini. It seems impossible to accept the remark- 

 able statements regarding the successful inoculation of insect flagellates to verte- 

 brates till definite confirmation is forthcoming. 

 The negative results obtained by so many com- 

 petent observers suggest that the positive results 

 reported may have been due to misinterpretations. 

 It is possible, however, that occasionally isolated 

 parasites may survive in the organs and give rise 

 to cultures, but it is doubtful if such a condition 



can be regarded as an infection. There is cer- _ ^ ^^^ 



tainly no reliable evidence that, even if such a ;'^i'^'^j<8'cf^^6^^^^E0 

 survival of the parasites occurs, they give rise to '^^iP'^^^^^jQ^'0^"'' 



serioixs and fatal disease. Though Fantham and '^'^*£?^*i^ \ ® ^^ 



Porter claimed that sticklebacks were killed by ^O^, ^}m 



the infections induced by feeding them on the 



intestines of the water bug, Hoare found that the ^IG. 185. -Vnjptoroccm muris 

 fish thrived on this diet. {^ ««• ^'^7„^-, ^^^^^^"^ 



There occur in the organs of rats and mice J^angiorgi, 19-...) 



structures which can readily be mistaken for 



leishmauia. Thus, Sangiorgi (1913) has described as Toxoplasma musculi certain 

 minute bodies found by him in the spleen of a mouse, and as T. ratti similar 

 forms from the rats. Sangiorgi (1922&) also recorded a Cryptococcus from mice, and 

 it is this organism which was named C. muris by Shortt (1923a), who discovered 

 it in mice in India (Fig. 185). Whether the structures described by Sangiorgi are 

 Toxoplasmata or not, it is evident that they and the cryptococcus could be easily 

 mistaken for leishmauia. The same remarks apply to the parasite of rabbits 

 described as Enceplialitosoon cuniculi and the similar form in mice, both of which 

 occur fairly commonly in the organs of laboratory animals (p. 754). 



INOCULATION OF INSECT TRYPANOSOMIDiE INTO INVERTEBRATES. 



As trypanosomes can be inoculated from one vertebrate to another, 

 so can invertebrates be inoculated with flagellates obtained from, other 

 invertebrates. Zotta (1912) observed a leptomonas in Pyrrhocoris aptera, 

 a plant bug. The infection occurred, not only in the intestine, but also 



