106 SCIENTIFIC AGRICULTURE. 



CHAPTER IX. 



ROTATION OF CROPS. 



177. What is meant by rotation ? 



178. What are its advantages ? Give illustrations. 



179. What other advantage is mentioned ? 



1 80. Give a third advantage of rotation. 



181. Give a fourth advantage. 



182. What is said of change of seed ? 



183. What crops should not follow each other ? What prin- 

 ciple should govern ? 



184. Mention a good three years' rotation. A four years' 

 rotation. An English rotation. 



185. A rotation for the tobacco-planter. For cotton-planter. 

 186 What is best to be done with the clover ? Why ? 



187. Have plants the power of secretion ? Of selection ? 



188. When will rotation certainly fail ? How can such 

 land be restored ? 



CHAPTER X. 



THE SELECTION AND CARE OF LIVE-STOCK. 



189. Why must every farmer have live-stock ? 



190. Upon what will the kind of stock to be kept depend ? 

 What sort should be selected ? Why ? 



191. What is necessary in the management of live-stock ? 

 Why? How should it be fed? Why should exposure be 

 avoided ? 



192. Difference between the functions of plants and animals ? 



193. How do animals digest their food and convert it into 

 bone and muscle ? 



194. What gas is formed in respiration ? How shown ? 



195. Why should animals require more food in cold than in 

 warm weather ? Why more when at work ? 



