ORDER QUADRUMANA. 841 



the junction of kindred species, the efficacy of which junction 

 must materially depend upon the vis generatrix of the min- 

 gled kinds. The orders rodentia and carnivora furnish us 

 with numerous applications of this law, as well as the Qua- 

 drumana. 



" The very productive character of the monkey race ought 

 therefore to give rise to considerable multiplication of the 

 species, and accordingly, we ascertain, on investigation, 

 that this is the real fact. In spite of the assiduous re- 

 searches of the greatest naturalists, it is seldom that we 

 survey a moderately-numerous collection of these animals 

 without discovering some new species, or some varieties 

 hitherto unknown. It is also far from doubtful, that if 

 their differences were more apparent, if they were consti- 

 tuted for example by marked and striking traits of colour, 

 our cabinets of natural history would be still better fur- 

 nished with such varieties than they are at present. But tri- 

 vial variations in the shades of gray, of brown, or of yellow, 

 slight changes in the length of the muzzle, the form of the 

 cranium, or the proportions of the members, were insuffi- 

 cient to command the attention of the generality of travel- 

 lers. The observation of such men is arrested only by ex- 

 treme differences, and it is a mere chance that the animals 

 which they import, evince, on being subjected to the inspec- 

 tion of the naturalist, such characters as are peculiar to 

 the species already known, whatever general similarity a 

 superficial observer may imagine to exist between them. 

 The frequent recurrence of such cases, evidently proves 

 how very numerous the species must be, and also what 

 farther accessions to their number may result from enter- 

 prising researches undertaken with a view to their disco- 

 very. The respective examination which we have made of 

 stuffed or living specimens of monkeys, has sufficed to con- 

 vince us of the utter impossibility of properly illustrating 



