SUPPLEMENTAL NOf^. 



iiot really more so than the habits of many savages, 

 instance that of rubbing their bellies with their hands, 

 rubbing noses together. The habit with the mandrill ai 

 drill seems to be instinctive or inherited, as it was foUowe 

 by very young animals; but it is modified or guided, like 

 so many other instincts, by observation, for Von Fischer 

 says that they take pains to make their display fully; and 

 if made before two observers, they turn to him who seems 

 to pay the most attention. 



With respect to the origin of the habit. Von Fischer 

 remarks that his monkeys like to have their naked hinder 

 ends patted or stroked, and that they then grunt with 

 pleasure. They often also turn this part of their bodies 

 to other monkeys to have bits of dirt picked off, and so 

 no doubt it would be with respect to thorns. But the 

 habit with adult animals is connected to a certain extent 

 with sexual feelings, for Von Fischer watched through a 

 glass door a female Cynopithemis niger, and she, during 

 several days, **umdrehte und dem Mannchen mit gur- 

 gelnden Tonen die stark gerothete Sitzflache zeigte, was 

 ich friiher nie an diesem Thier bemerkt hatte. Beim 

 Anblick dieses Gegenstandes erregte sich das Mannchen 

 sichtlich, denn es polterte heftig an den Staben, ebenfalls 

 gurgelnde Laute ausstossend.^' As all the monkeys which 

 have the hinder parts of their bodies more or less brightly 

 colored live, according to Von Fischer, in open rocky 

 places, he thinks that these colors serve to render one sex 

 conspicuous at a distance to the other; but as monkeys are 

 such gregarious animals I should have thought that there 

 was no need for the sexes to recognize each other at a dis- 

 tance. It seems to me more probable that the bright 

 colors, whether on the face or hinder end, or, as in the 

 mandrill, on both, serve as a sexual ornament and attrac- 

 tion. Anyhow, as we now know that monkeys have the 

 habit of turning their hinder ends toward other monkeys, 

 it ceases to be at all surprising that it should have been 

 this part of their bodies which has been more or less 

 decorated. The fact that it is only the monkeys thus 

 chai*acterized which, as far as at present known, act in this 

 manner as a greeting toward other monkeys renders it 

 doubtful whether the habit was first acquired from some 

 independent cause, and that afterward the parts in ques- 

 tion were colored as a sexual ornament; or whether the 



