I.J ZOOLOGY OF THE ISLAND. 15 



quality, but a considerable quantity is annually exported, the 

 amount increasing from year to year. In 1881 ninety-six thousand 

 piculs of 133 pounds passed through the Customs. 



Birds appeared to be numerous in the jungle by the river side, 

 the black Drongo-shrike {Chaptia hrauniana) especially so, while 

 the clear note of a Barbet {Megalcema nnclialis) was audible in all 

 directions. Both these birds are peculiar to Formosa. They have 

 no representatives on the mainland of China, and their closest 

 allies are to be found in North India and Sumatra. A closer study 

 of the Formosan avifauna shows that this tendency to Indian and 

 Malayan, rather than to Chinese forms is most striking. The 

 island boasts of no less than forty-three species peculiar to it — an 

 enormous number when we consider the fact that the Chinese coast 

 is barely sixty miles distant — and, of these, twenty are representa- 

 tives of regions other than the adjacent mainland. The same 

 tendency is noticeable, perhaps to an even greater degree, among the 

 mammals. 



The above facts, our knowledge of which is almost entirely due 

 to the late Mr. Swinhoe, teach us firstly that, as Mr. Wallace has 

 shown,^ Formosa should be classed among the recent continental 

 islands, and also that, at the time of its connection with the 

 mainland the ancestors of the Formosan, Indian, and Malayan 

 forms were equally dispersed throughout the intervening and at 

 that time undivided continent. After the separation of Formosa 

 and the Malayan islands the altered geological and climatological 

 conditions were such as to cause the disappearance of many forms 

 of animal life except in localities wliere the required conditions, 

 such as dense forests or high mountain ranges, still remained. The 

 immense number of peculiar species, however, tend to show that 

 Formosa must have become detached from the mainland at some 

 tolerably remote period, for we know, from a consideration of our 

 own, as well as of other islands, that the process of formation of a 

 species is one of a by no means rapid character. 



1 "Island Life" A. R. Wallace, p. 371. 



