THE PLANT AND ITS FOOD 21 



of sunlight, which enables it to construct com- 

 plex carbon compounds when supplied with the 

 raw materials, carbon dioxide and water. In 

 other words, the chloroplast is a mechanism 

 which is able to build up carbon compounds 

 which are poorer in oxygen than are the raw 

 materials upon which it works, and thus the 

 kinetic energy supplied by the sunlight be- 

 comes converted into the potential energy re- 

 presented by the chemical products which are 

 formed as the result of chloroplastid activity. 

 This energy (which was derived from the sun), 

 can again be released by oxidation, that is 

 by more or less rapidly burning those products. 

 It may then be utilised to heat a furnace, to 

 drive a steam engine, or to maintain the bodily 

 processes of a man. 



This property of the chloroplast is of funda- 

 mental importance, not only for the plant, 

 but for animals as well, for every animal is 

 directly or indirectly nourished by vegetable 



Products, which form the starting-point of the 

 :>od-supply of the world. In the absence of 

 chlorophyll there would be none of the higher 

 plants as we know them, nor would there, in 

 all probability, be any of the higher animals 

 at all. In this sense we are indeed all children 



may be termed a syncytium., It must be borne in mind 

 that the membrane is not an essential feature of cells, 

 although in plants, as stated in the text, it is of very general 

 occurrence. The cell contains other Bodies, e. g. chloro- 

 plasts, starch, oils, etc., but these are non-essential, and 

 are often absent. 



