CHAPTER VIII. 



PLANTS AND ANIMALS. 



IF an argument were needed in favour of the study 

 of botany, no better could be urged, or required, than 

 a statement of the obligations which man, in common 

 with all animals, is under to the vegetable kingdom. 

 There is no necessity, and there is no possibility, of 

 exaggerating this obligation, for man himself, " the 

 lord of creation," is absolutely dependent upon plant- 

 life for his existence. Were all vegetable-life with- 

 drawn from this globe, animal-life would quickly 

 cease, so intimate is the connection between animals 

 and plants. We have seen in our second Chapter 

 how the plants consume the poisonous carbon with 

 which the respiration of animals has polluted the air, 

 and how they give out the oxygen which is abso- 

 lutely necessary for our existence. This explains 

 why large towns are less healthy than the country 

 an explanation which until recently the town popu- 

 lations, or, rather, the municipal authorities, have 

 ignored ; and so the towns have gone on extending 

 their boundaries, covering with bricks and 'mortar 

 the surrounding fields and lanes, cutting down trees, 

 and otherwise shutting out the country and decreas- 

 ing the healthiness of the city. " If a man walk in 



