PROTOZOA OF LATEX PLANTS 259 



discovered in the milky juices of plants by Lafont in Mauritius 

 in the year 1909. Similar flagellates were soon described by 

 other investigators throughout the tropics and subtropics. This 

 made it evident that herpetomonads inhabit the latex cells of many 

 plants as characteristically as other herpetomonads inhabit the 

 intestinal tracts of insects. These protozoa of plants depend 

 upon insects to carry them from plant to plant, and when in 

 the insects they multiply in the intestinal tract and in the salivary 

 glands. 



The flagellate species first reported from Mauritius by Lafont 

 in 1909 was given the name Lcptomonas daz'idi Lafont. It was 

 found in the latex of Euphorbia piluUfcra by his assistant, David, 

 whom he had asked to examine the milky juices of these plants 

 to discover whether they might be good culture media. After 1909 

 reports of the presence of latex flagellates came from India, Re- 

 union, Madagascar, Mayotte, Zanzibar, Dahomey, Upper Senegal 

 and Niger, Martinique, Portugal, Belgian Congo and Xew Cale- 

 donia. Later reports came from Sardinia, Italy, Paraguay, and 

 Venezuela. Recently reports have come from France, Switzerland, 

 Algeria, Uruguay, Alsace, Honduras, the United States of Amer- 

 ica, Central America, Roumania, Brazil, South Africa, and Queens- 

 land. 



A map showing this very nearly world-wide distribution of 

 latex flagellates is shown in Fig. 16. As the map indicates, certain 

 portions of the world have been more thoroughly investigated than 

 others. The islands of the Indian Ocean, much of Africa, the 

 countries of southern Europe and the eastern coast of North and 

 South America have been examined to some extent; in a few 

 localities extensive studies have been carried on. Some portions of 

 the world, notably the countries of the Far East, the southern 

 United States, Mexico, and parts of South America have received 

 little attention. There are few locations within the indicated gen- 

 eral range in which a careful survey has failed to bring to light 

 some species. The uninvestigated regions in the tropics and sub- 

 tropics are probably furnished with abundant instances of latex 

 plant infections by protozoa of this group. It remains only for 

 investigation to be made in these countries to bring to the attention 

 of the world new species of latex protozoa, new insect hosts 

 and new plant hosts in considerable numbers. It is to be hoped 

 that investigators who may be able to survey these regions in 



