WHAT IS A PLANT? 161 



these simple bodies they can, by taking away their oxygen^ build up 

 their own compound substances, such as starch, cellulose, and the 

 nitrogenous body, protein, which forms the chief part of their proto- 

 plasm ; i.e., they are able, out of these simple substances above 

 named, together with some phosphates and sulphates — the " raw 

 materials " — to build up their own vegetable " stuffs." They are 

 producers. 



Animals, on the contrary, are, for the most part, unable to do 

 this. They need their protein ready made for them. They live, 

 therefore, on plants, or plant-eating creatures, which contain 

 starch, sugar, protein, etc. ; these they bi-eak doivn into simpler 

 bodies, and by adding oxygen to these (the reverse of the plant 

 process), they reproduce the water, carbonic acid, and ammonia, 

 destined again to be given off, and to become the food of 

 plants. They are consumers. So the circle of life is kept up, and 

 to use Huxley's apt terms, animals are the " ideal aristocrats," as 

 opposed to plants, which are the " working classes " ! The plant 

 process is one of deoxidation and synthesis ; the animal process is 

 one of analysis and oxidation, or combustion. 



Now, this ina7iiifacturing power possessed by plants is the only 

 sharp line of demarcation that we can find that shall separate 

 them from animals. Even to this, sharp and clear as it is, there 

 are modifications, to use a milder term than that of exceptions. 

 Let us glance at a few of these. 



Many of the higher plants — the parasites, before named, as 

 also the Fungi, or moulds — having no chlorophyll, are unable to 

 decompose the simple inorganic bodies, and so to use them as 

 food ; still, they are manufacturers, for if we supply them with 

 bodies slightly more complex, such as ammonia tartrate (contain- 

 ing carbonic acid), they can build up their protein from these, and 

 are therefore plants. Suppose we sow a single spore of Fe?iicil- 

 lium, the mould found on old boots, or on jam, in a solution 

 containing ammonia tartrate, with a small addition of phosphates 

 and sulphates, keeping it warm, in either darkness or light, we 

 shall shortly find a thick film of mould many million times the 

 weight of our spore in cellulose, protein, etc. 



All this has been manufactured. No sunshine, no chlorophyll, 

 and yet work done \ proving that manufacture can go on inde- 



