244 ' CATECHISM OF 



What do you say of the flower-leaves (petals, . 148. Does this 

 give them their colors ? 148. How? 148. 



After flowering, what seems to be their principal effort ? 149. 

 Is the growth always a measure of fruitfulness ? 149. What is 

 said of manuring corn wholly in the hill? 149. What of 

 corn-roots ? 149. Should all the manure then be in one place ? 

 149. 



Is late hoeing injurious ? 150. Why? 150. Will you explain 

 this fully? 151. 



With regard to the circulation of plants, what may be taken 

 as a sort of sample ? 153. Of what does the stem consist ? 154. 

 What of the pith? 155. Describe the roots? 156. What are 

 the spongioles? 157. Describe the rootlets? 158. 



What is said of the branches and twigs? 159. What are the 

 leaf-stems? 160. What flows through them? 160. What does 

 the circulation of the sap through the leaves resemble? 160. 

 Describe the leaves ? 160. 



When the sap has circulated through the leaves, what takes 

 place? 161. How is the annual layer of wood formed ? 161. 



What is the destiny of all. that lives ? 162. On what do men, 

 brutes and plants hve ? 162. What of the floating matter around 

 us? 162. What is probable ? 



What does the plant devour? 163. What happens to it in 

 return? 163. 



When plants have passed their maturity, what happens ? 164. 

 What are their proximate constituents ? 164. What secondary 

 products come from these ? '^ 



What is said of starch? 165. Of sago? 165. Of arrow-root ? 

 165. Of tapioca? 165. Of all these? 165. 



Of what are starch, gum and sugar composed? 166. Of what 

 are gluten, caseine and albumen composed ? 167. Why are they 

 called nitrogenous ? 167. What do they contain besides the 

 organic elements ? 167. Do one or more of them exist in all 

 plants? 168. 



What can you say of gluten? 169. Of caseine? 170. Of 

 albumen ? 171. How can you separate the constituents of flour ? 

 172 and 173. 



Which of the substances just spoken of contain nitrogen ? 

 174. What else ? What letters then may characterize them ? 

 174. Which contain no nitrogen? 175. What letters may 

 characterize these ? 166. Which are most nutritious, as food ? 

 175. 



What remarkable fact is stated of starch, gum and sugar ? 175. 

 In what proportions are the oxygen and hydrogen in them? 175. 

 Is the same true of woody fibre ? 175. Of what then do they 

 consist? 



Are starch, gum and sugar identical in composition ? 175 and 

 176. Of what transformations are they capable ? 176. 



