SS Introduction: Wallace's line. 



assigned to the great Sunda Islands, 3 to the eastern islands, that, therefore, 

 no sharp frontier exists for land-shells between Bali and Lombok. 



The same eminent conchologist said in 1897 ("Siiss- und Brackwasser-Mol. 

 des Indischen Archipels": Weber's Zool. Ergebnisse IV, 298): "The frontier between 

 Bali and Lombok is for the fresh-water MoUiisca quite imaginary, as long as we know 

 next to nothing of the species living on these islands;" and he proved further 

 (p. 297) that the fresh-water MoUusca from South Celebes are most closely 

 allied to those of Java and Flores, those of North Celebes most closely to those 

 of the Philippines, which is not consistent with Wallace's line, but with the 

 geographical position. 



A. Supan, 1896 ,"Grundzuge der physischen Erdkunde", p. 557, and Maps 

 XIX, XX) sticks to the "celebrated" line. 



W. Kiikenthal, in 1896 (Abh. Senckenb. Naturf. Ges. XXII, 130), abnegates 

 Wallace's line. 



W. L. Sclater, 1896, treating of the Mammals of his Celebesian Subregion 

 i"The Geography of Mammals'": Geogr. Journ. VHI, 388 with Maps), tind.s that the 

 Australian element in the mammalian fauna of Celebes does not in any way 

 require the supposition of an ancient land-connection with that Region, but that 

 the greater amount of Oriental forms suggests such a former connection with Asia; 

 he, therefore, annexes the Celebesian Subregion to the Oriental and not to the 

 Australian Region. In the beginning of this important paper (1. c. 1894, III, 

 p. 97, with Map, and IV, p. 35, with Map Mr. Sclater draws Wallace's line 

 to the east of Celebes and between Bali and Lombok (see, also. 1. c VIII, p. 378) 

 and takes this as the frontier between the Australian and the Oriental Region, 

 reckoning the Sula Islands to the former, Celebes to the latter, as "on the whole 

 the evidence of the mammals, at any rate, serves to connect it more closely with 

 the Oriental Region" see 1. c. IV p. 36). 



F. J. Nierraeyer, finally, in 1897 ("De Geschiedenis van de lijn van 

 Wallace": Tijdschr. Kon. Ned. Aard. Gen. 2. ser. XIV, 758), has given a very 

 readable historical sketch. He rightly censures zoologists, botanists, and geo- 

 graphers for often writing on the problem without having consulted Wallace 

 himself, or the manifold literature extant on this subject, and still advocating 

 a frontier which specialists have long since abandoned. He shows in detail how 

 Wallace himself has altered his opinion from 1860 to 1863, 1869, 1876, and 

 1880, and what Weber's merits are in promoting knowledge on this question. 



On going over these different opinions on Wallace's line it will be seen 

 that they are fairly equally divided, though they must be weighed and not 

 counted, many writers on the general subject not plunging deeply into the 

 problem, but uncritically following the authority of this eminent naturalist. 

 One must also take into account that errors, when once they have crept into 

 books, disappear from them with great difficulty. On the other hand also, some 



