THE CHIMPANZEES AND ORANGS. 177 
The Pithecus Morio may, therefore, quoad its origin, be an old-established, and now 
permanent, dwarfed variety of the Pith. Satyrus. I apprehend that few naturalists, 
now-a-days, in describing and proposing a name for what they call ‘‘ a new species,” use 
that term to signify what was meant by it twenty or thirty years ago, that is, an 
originally distinct creation, maintaining its primitive distinction by obstructive gene- 
rative peculiarities. The proposer of the new species now intends to state no more 
than he actually knows ; as for example, that the differences on which he founds the 
specific character are constant, in individuals of both sexes, so far as observation has 
reached ; and that they are not due to domestication or to artificially superinduced exter- 
nal circumstances, or to any outward influence within his cognizance ; that the species 
is wild, or is such as it appears by nature. It becomes, therefore, a matter of con- 
venience, if not of necessity, to indicate the species by a distinct name, in the imparting 
of zoological knowledge. 
The justification of such a procedure depends on the kind and degree of evidence, 
and I believe that I have at length been enabled to record such evidence, in regard to 
the Pithecus Morio, in the ‘ Transactions of the Zoological Society.’ 
DESCRIPTION OF THE PLATES. 
PLATE XLVIII. 
Side view of the skull of an adult male Pithecus Morio: nat. size. 
PLATE XLIX. 
Fig. 1. Base view of the same skull: nat. size. 
Fig. 2. Grinding surface of the lower teeth, right side: nat. size. 
PLATE L. 
Fig. 1. Top view of the skull of an adult male Pithecus Satyrus, var. Pappan : halt 
nat. size. 
Fig. 2. Grinding surface of upper molars and canine, left side: nat. size. 
Fig. 3. Top view of the skull of an aged male Pithecus Satyrus (the variety called 
Mias Rambi by Blyth), with separated temporal ridges: half nat. size. 
Fig. 4. Grinding surface of upper molars and canine, left side: nat. size. 
Fig. 5. Grinding surface of lower molars and canine, right side: nat. size. 
