442 ISLAND LIFE part ii 



A few Mascarene genera are found elsewhere only in 

 South America, Australia, or Polynesia ; and there are 

 also a considerable number of genera whose metropolis is 

 South America, but which are represented by one or more 

 species in Madagascar, and by a single often widely 

 distributed species in Africa, This fact throws light upon 

 the problem offered by those mammals, reptiles, and 

 insects of Madagascar which now have their only allies in 

 South America, since the two cases Avould be exactly 

 parallel were the African plants to become extinct. 

 Plants, however, are undoubtedly more long-lived speci- 

 fically than animals — especially the more highly organised 

 groups, and are less liable to complete extinction through 

 the attacks of enemies or through changes of climate or 

 of physical geography; hence we find comparatively few 

 cases in which groups of Madagascar plants have their 

 only allies in such distant regions as America and Aus- 

 tralia, while SQch cases are numerous among animals, 

 owinof to the extinction of the allied forms in interveninsc 

 areas, for which extinction, as we have already shown, 

 ample cause can be assigned. 



Chcrious Relations of Mascarene Plants. — Among the 

 curious affinities of Mascarene plants we have culled the 

 following from Mr. Baker's volume. Trochetia, a s^enus 

 of Sterculiaceoe, has four species in Mauritius, one in 

 Madagascar, and one in the remote island of St. Helena. 

 Mathurina, a genus of Turneracese, consisting of a single 

 species peculiar to Rodriguez, has its nearest ally in 

 another monotypic genus, Erblichia, confined to Central 

 America. Siegesbeckia, one of the Compositse, consists 

 of two species, one inhabiting the Mascarene islands, the 

 other Peru. Labourdonasia, a genus of Sapotacese, has 

 two species in Mauritius, one in Natal, and one in Cuba. 

 Nesogenes, belonging to the " verbena family, has one 

 species in Rodriguez and one in Polynesia. Mespilodaphne, 

 an extensive genus of Lauracese, has six species in the 

 Mascarene islands, and all the rest (about fifty species) in 

 South America. Nepenthes, the well-known pitcher 

 plants, are found chiefly in the Malay Islands, South 

 China, and Ceylon, with species in the Seychelles Islands, 



