24 ZOOLOGY. 



nent moutli nor any digestive organ whatever. No trace 

 of a nervous system has been observed. 



In the Infusoria locomotion is effected by cilia, which 

 are kept perpetually in motion. The lower forms have 

 the power of extemporizing processes termed pseudopodia 

 (Or. pseudos, false ; poda, feet). These are sometimes 

 finger-like, and sometimes fine filaments resembling 

 minute threads. 



This sub-kingdom has been divided into three classes : 



1. Infusoria (so called because they are met with in 

 infusions of vegetable matter). 



2. Rhizopoda (Or. rhiza, root ; poda, feet). 



3. Gregarinida (Lat. gregarius, occurring in flocks). 



QUESTIONS. L 



1. Strictly speaking, what sciences are included in "Natural 



History"? 



2. What is the popular use of this term ? 



3. What are the two great divisions of natural objects ? 



4. What is Biology, and what sciences does it include? 



5. Define Zoology. 



G. What are the leading distinctions between organic and in- 

 organic bodies ? 



7. What are the principal differences between plants and 



animals ? 



8. What substances do living animals and plants respectively 



contribute to the atmosphere ? 



9. Name the primary groups of animals, and the classes into 



which they are subdivided. 



10. What are the principal characters of the sub-kingdom 



Vertebrata ? 



11. What are the principal parts of the vertebrate skeleton ? 



12. Describe the nervous system. 



13. How are the brain and spinal cord protected ? 



14. How does a transverse section of a vertebrate animal differ 



from a similar section of an invertebrate ? 



15. How many limbs have the Vertebrata, and what arc the 



exceptions to this rule ? 



16. How does the heart differ in the various groups ? 



17. What is the nature of the blood ? 



18. What are " corpuscles " ? 



19. What vertebrate animal has colourless blood ? 



