NATURAL HISTORY. 



[Lesson III. 



dotn. Thus, the animal kingdom has tour 

 sub-kingdoms, each of which includes all 

 animals possessing certain peculiarities, 

 which will be noticed as we proceed. 



21. T. What is a CLASS? 



P. It is the first division of a sub- 

 kingdom. 



22. T. What is an ORDER ? 



P. A division in eluding several families. 



23. T. What is a TRIBE ? 



P. A group between a family and an 

 order. Thus the order Incessores, or perch- 

 ing birds, has several tribes, which are 

 again divided into families or groups, con- 

 taining many sub-families. 



24. T. What do you mean by a GENUS ? 

 P- It is a number of species closely 



resembling each other, but yet differing 

 slightly in some point; in fact, a collec- 

 tion of sub-genera. 



25. T. What is a SUB-GENUS ? 



P. Several species, all of the same type 

 of formation. 



26. T. What is a SPECIES ? 



P. It is an animal distinguishable from 

 another animal on account of certain pe- 

 culiarities of structure, size, or otherwise. 



27. T. Are all the individuals of one 

 species alike ? 



P. Yes, they all resemble the parent. 



28. T. Is there not another division 

 which naturalists notice ? 



P. Yes, varieties. These are generally 

 the result of accident, such as food, si- 

 tuation, or malformation, and do not per- 

 petuate their peculiarities. 



[The pupil should be required to give some 

 examples of the causes of varieties, such as 

 unusual heat or cold, scarcity of food, &c.] 



29. T. You have now learned that 

 there are certain points for the practical 

 naturalist to attend to ; and, as the vege- 

 table and mineral kingdoms will be exa- 

 mined hereafter, we must now confine our- 

 selves to the principles of classification in 

 the animal kingdom alone. 



GENERAL QUESTIONS ON LESSON II. 



1. Why do we have fixed names for 

 objects of Natural History ? 



2. What is the usual method of dividing 

 Natural History ? 



3. Why is the Linnaean system not so 

 good as the Cuvierian ? 



4. What do you mean by the terms 

 kingdoms, sub-kingdoms, classes, and 

 orders ? 



5. Explain the meaning of the terms 

 tribes, families, and sub families. 



6. What is the difference between a 

 genus, sub-genus, and species? 



7. Are varieties perpetuated ? 



8. Why are not varieties perpetuated I 



LESSON III. 



IT is the aim of scientific men to classify and arrange the various objects of Natural 

 History that surround them ; and, in doing so, they have to confine themselves to 

 certain laws. They observe the difference in structure of animals from plants the 

 habits, actions or functions, and peculiarities of each. Those animals or plants that closely 

 resemble each other are grouped together, and naturalists have found that certain 

 individuals possess the means of perpetuating their species : thus we know that pointers 

 will not produce spaniels, or vice versa ; and therefore we commonly call such a series 

 of families a race. It is our duty to endeavour to discover whether these races have a 

 common origin ; for instance, Is it possible that all dogs, of whatever breed, are 

 descended from two parents? Naturalists must pay attention to the anatomical struc- 

 ture of animals, before they can classify them correctly. The Animal Kingdom is 

 divided into four sub-kingdoms VERTEBRATA, MOLLUSCA, ARTICULATA, and RA- 

 DIATA ; and we shall now consider their principal characteristics consecutively. 



