CHAPTER VI 



THE MANUFACTURE OF ORGANIC FOOD 



ON p. 27 we saw that it was only the green plant that 

 was able to manufacture organic compounds from 

 inorganic materials, for long erroneously spoken of 

 as the " food " of plants. The " food " of the plant, 

 just as much as that of the animal, must be organic 

 in its nature, and since, in the liberation of energy, 

 these compounds are constantly being reduced once 

 more to simpler inorganic compounds by the process 

 of oxidation, it follows that a mechanism must be 

 forthcoming for the remanufacture of the complex 

 compounds so destroyed, else the whole living machi- 

 nery of the globe would come to a standstill. Further, 

 not only must there be a constructing apparatus, but 

 energy must be supplied to it else the mechanism 

 would be unable to work. It must now be our task 

 to inquire into the nature of this apparatus and the 

 source of the energy in other words, to study the 

 chlorophyll machinery, the chloroplasts, referred to 

 on p. 10, and the nature of sunlight. 



Our conception of the sequence of events that 

 take place in the process of nutrition in plants and 

 animals will become much clearer if we endeavour 

 to realise that the chlorophyll apparatus is not neces- 

 sarily a part of the plant only ; there are many plants 

 which are destitute of chlorophyll, and not a few 

 animals which possess it. Indeed, a near ally of the 

 species of Hydra which we studied from another 

 aspect in a previous chapter, is, owing to the presence 



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