Flagellates of Laticiferous Plants

Since flagellates have been reported to be present in a large number of laticiferous plants, the increased interest in the possibility of using these plants for sources of rubber, and their introduction into the agriculture of new regions of the United States and other American countries has made desirable further studies on these organisms. After the statement was published by Hegner (2) that flagellates had not been found commonly in economic rubber plants, their occurrence in Taraxacum kok-saghyz has been reported by Isakova (4). A survey of the literature shows that they have been reported for a number of rubber plants in their native habitats. The introduction of such plants into extensive culture may make more frequent the usually sporadic occurrence of these flagellates, provided their insect vectors also become more prevalent in mass cultivation of the host plants used for rubber production. Without the presence of natural vectors, infestation may be present only in plants vegetatively propagated since the flagellates have not been shown to be transmitted through seed. Some of the laticiferous plants have been suspected of being reservoirs for flagellates that produce animal and human infections causing tropical ulcers. Various skin ulcers of the Brazilian type of Leishmaniasis are said to be very common among persons who are engaged in clearing uncultivated woodlands, as in the clearing of rubber plantations (7). The transmission of plant flagellates to mammalian hosts, however, has been only occasionally successful. Strong (9) found flagellates morphologically identical in the latex of a Euphorbia, in a hemipterous insect feeding on this plant, and in a lizard feeding on the insects ; he produced a skin ulcer in a monkey by injecting the intestinal contents of the lizard. Non-flagellate forms from the ulcer were morphologically similar to Leishmania.