THE MONKEYFOLK OF SOUTH AFRICA 123 



who are separated from us and placed in what naturaHst 

 men call a sub-family hy themselves, because they only 

 have rudimentary thumbs, or no thumb at all, so they are 

 called Colobus monkeys, from a Greek word which means 

 " docked." Besides, these Colobus monkeyfolk differ from 

 us in not having any cheek pouches. 



Now we Guenon monkeys of Africa all have cheeks 

 which can stretch like india-rubber. We use these pouches 

 for storing food when we are in a hurry. You see, by means 

 of these pouches we can cram quite a lot of food into our 

 mouths in a very short time. Then we rush off to our 

 safe retreats, and eat it up at our leisure. Another thing 

 which makes naturalist men separate us from our first 

 cousins, the Colobus or Guereza monkeys, is that we have 

 simple bags for stomachs like humanfolk ; whereas our 

 cousins have what you call sacculated stomachs, which 

 means their stomachs are like a lot of little sacs stuck to- 

 gether. A sac is a membranous pouch — a cavity or re- 

 ceptacle. Another difference is that our arms and legs 

 are about the same length, whereas the legs of the Colobus 

 or Guereza monkeys are longer than the arms. 



SYSTEMATIC ZOOLOGY 



I am explaining all this to you so that you might have 

 some idea of what is meant by systematic zoology. You 

 see, although the Guereza monkeys have many things in 

 common with us Guenons, they all have those sacculated 

 stomachs and are minus thumbs ; so all monkeys of that 

 kind are classed in a sub-family by themselves, and separated 

 into different species according to little differences in their 

 teeth formation, colour, shape, &c. Although we Guenon 

 monkeys all have arms and legs about the same length, 

 cheek pouches, and simple stomachs, yet there are many 

 different kinds of us. For instance, there is a great difference 



