90 BIOLOGY AND HUMAN LIFE 



a. Lemuroidea. Small, squirrel-like animals living in trees and 



bushes. The lemurs are found in Madagascar, the mar- 

 mosets in South America. 



b. Cebidae. The New World monkeys. Nearly all have long, 



grasping tails and flat noses. Smaller than the Old World 

 monkeys. {Examples. Howling monkey, spider monkey, 

 capuchin.) 



c. Cercopithecidae. The Old World monkeys. Tail not grasp- 



ing, or short ; nostrils pointing downward. Distinct, oppos- 

 able thumb. {Examples. Baboons, mandrill, macacus.) 



d. Simiidae. The anthropoid (manlike) apes. No distinct tail ; 



arms longer than legs. {Examples. Gibbons, orang-utans, 

 chimpanzees, and gorillas.) 



e. Hominidae. The human race. 



QUESTIONS 



1. Why are there two names for each kind of plant and animal? 



2. In what sense is the cat related to the tiger or lion ? 



3. What is meant by saying that one species is related to another ? 



4. W^hat do we need to know about a plant or an animal before we can 

 tell in what group to place it ? 



5. In what ways are the different plants in one branch alike ? 



6. In what ways are the different animals in one branch alike ? 



7. How can you tell to what class a particular animal belongs, even if 

 you do not know what particular kind it is ? 



8. How is it that a plant or an animal belonging in one group can be 

 mistaken for one in another group ? 



9. WTiy do people keep on changing the classifications of organisms ? 



REFERENCE READINGS 



BiGELOW. M. A. Applied Biology, chap, vii, Classification of Animals 

 and Plants. 



Moon, T. J. Biology for Beginners, chap, xxi. Arthropods. 



CocKERELL. T. D. A. Zoology, chap, xxii, Principles of Classification. 



Calkins, G. Biology, pp. 162-172. 



Any convenient manuals for the identification and classification of com- 

 mon plants, including trees, ferns, mosses, and fungi, and of common 

 birds, insects, fishes, batrachians, mammals, etc. 



