386 FAMILY: TRYPANOSOMID.E 



boured hemiptera, and in one of these, Nysius ewphorhice, he found a 

 flagellate of the leptomonas type. He succeeded (1911) in infecting 

 healthy plants by means of these bugs, but failed to infect E. peplus, 

 which is never found naturally infected in Mauritius, Bouet and 

 Roubaud (1911), employing eighty specimens of the bug Dieuches humilis, 

 also succeeded in carrying infection from one plant {E. pilulifera) to 

 another. Rodhain and Bequaert (1911) observed flagellates in the intestine 

 of an hemipteran larva taken off infected Euphorbia indica in the Congo. 

 Franga (1919 and 1920a), working in Portugal with E. segetalis, has 

 succeeded in transmitting the infection by the agency of a bug, Steno- 

 cephalus agilis (Fig. 183). The bug is chiefly nocturnal in its habits, 

 and, when feeding, punctures the leaf in many places. The points of 

 puncture — the primary lesions — when examined, are found to contain 

 minute rounded or slightly elongate forms of the flagellate, which are 

 very similar to those which occur in the salivary glands of the bug. It 

 is later that the infection extends from the primary lesion to the latex, 

 and becomes general. Franga has traced the development of the flagellate 

 in the bug up to an invasion of the salivary glands (Fig. 184). The forms 

 ingested by the bug when feeding on infected latex multiply rapidly in 

 the gut up to the fourth day. It is supposed that there then occurs a 

 process of syngamy, in which two flagellates, after losing their flagella 

 and kinetoplasts, fuse completely. Unfortunately, this appears to have 

 been deduced from stained films only, so that it cannot be accepted as 

 reliable. From the fourth day onwards there appear large giant forms 

 up to 50 microns in length, and rounded multinucleate bodies. After 

 this period, only small forms 4-5 to 7 microns are found. These are, 

 presumably, the infective forms, for they occur, not only in the gut, but 

 also in the salivary glands. Small round leishmania forms, some of which 

 appeared to be encysted, were found occasionally in the hind-gut, and 

 once in the proboscis. Invasion of the salivary glands seems to take 

 place by a forward migration of the intestinal forms, which make their 

 way to the proboscis and thence up the salivary duct, as in the cycle of 

 development of Trypanosoma gambiense in tsetse flies. Flagellates were 

 not found in the hsemocoele fluid, though a dipterous larva (one of the Ocyp- 

 terincB or G^^/mnosominoe), inhabiting the body cavity, was found infected. 

 Galli-Valerio (1921), working in Switzerland, has found Euphorbia 

 gerardiana infected at a height of 1,300 metres above sea-level. The plants 

 provided one specimen of Stenocephalus, and in this bug he claims to have 

 found the intestinal flagellates and the small metacyclic forms in the 

 salivary glands described by Fran9a. Franchini (19226) collected the insects 

 and bugs from a large number of infected Euphorbias near Bologna. In no 

 case was Stenocephalus found, and it is concluded that other arthropods 



