432 THE HON. WALTER ROTHSCHILD ON [DeC. 13, 



Chimpanzees, but seeing that we are faced by two distinct problems, 

 when trying to classify the large red apes of Borneo and Sumatra, 

 I think the present arrangement clears up a few difficulties and 

 is an advance on foi-mer classifications. The first of the above 

 problems connected with the Orangs is, that throughout their 

 entire range two forms are found living side by side which are 

 extremely difiierent in appearance. In one of these the adult 

 males are very large and have huge callosities on each side of the 

 face, in the other the adult males are smaller and have no sign of 

 any face- {i. e. cheek-) callosities. There is considerable diversity 



Text-fia-. 113. 



Head of Simia pygmmus Sclireber. (From life.) 



of opinion as to what is the correct position to assign to these two 

 forms. Professor Matschie not only considei's them to be distinct 

 species, but even goes so far as to say they are distinct genera. I 

 cannot at all agree to even considering them distinct species, but 

 feel sure they are only dimorphic phases of one species. 



The second problem presented by the Orang-Outans is whether 

 there are a number of different species or whether there is only 

 one variable species consisting of a number of geographical races 

 or subspecies. 



Professor Matschie inclines to the former view, wliile Dr. Selenka 



