286 THE INFLUENCE OF INANIMATE SURROUNDINGS. 



two species to Mindanao, of which one (A. maculiferus) extends 

 as far as Bohol and the south coast of Leyte, while the other (A. 

 ch'oris) is found only on the south-west point of Mindanao. 

 Three species of the genus Xesta, which is at least equally cha- 

 racteristic of the Malayan islands and even of India itself, 

 as the two species of Amphidromus above mentioned, have the 

 same distribution ; two of them have hitherto only been found 

 in Mindanao (X. Antonii and nobilis), the third (X. Cumingi) 

 lives in Mindanao, Camiguin de Mindanao, and Bohol ; and since, 

 moreover, the number of typical Philippine species is very 

 inconsiderable in Mindanao compared with the others, the 

 remai-kable encroachment of Indian forms on the south Philip- 

 pine province is all the more conspicuotis. 



Hence, having regard to these differences, the Philippines 

 may be divided into three regions : I. The northern, which ex- 

 hibits in some degree the Chinese character. II. The south- 

 ern, which has Malayan or Australian affinities. III. The 

 Median, which may be called typically Philippine, since it 

 has scarcely any admixture of foreign elements. This result 

 is confirmed when we come to consider the other animals in the 

 islands. The stag of the Philippines has, so far as I know, 

 hitherto been found only in the north of the archipelago, and 

 its nearest allies are in China. Galeopithecus and Tarsius, 

 both highly characteristic of the Indian Islands, only occur 

 in the southern Philippines, and never in Lxizon ; an apparently 

 new species of the Malayan genus Cladobates is found only 

 in Mindanao. One single species of Barbus, a fish, I found 

 only in Mindanao ; this genus is represented in the Malayan 

 islands by very numerous species ; and the singular Platyptera 

 aspro, of the family of Gobioidse, in the same way occurs 

 only in the south of the Philippines. Among reptiles, A mbly- 

 cep/ialus boa, Dipsas dendrophila, Tropidophorus Grayi, and 

 Ptychozoon homalocephahim, all living exclusively in Min- 

 danao, belong to the purely Indian fauna. The same mixture 

 of autochthonous species with Indian species in the south, and 

 Chinese in the north, is displayed by the butterflies, as my brother, 

 George Semper, informs me. from studying my collection of 

 insects. 



