224 BIOLOGY 



groups of plants that have quite lost their chloropnyll (toad- 

 stools, molds, etc.), there is no longer any difficulty in deter- 

 mining that they are to be grouped with plants rather than 

 with animals, in spite of their not having any green color- 

 ing matter. When, too, we find a plant like the sundew (Fig. 

 104), which captures insects by means of the hairs on its leaves, 

 and digests and assimilates them, we call it a "carnivorous 

 plant" (Lat. caro (carnis) = flesh + vorare = to eat), but do not 

 confound it with animals. The Metazoa (Gr. meta = after -f 

 zoon = animal) and Metaphyta (Gr. phyton = plant) are sharply 

 distinct. 



CONTRAST BETWEEN THE ACTIVITIES OF ANIMALS AND 



PLANTS 



The similarities and differences between animals and plants 

 may be better understood if their properties are contrasted 

 with each other in regular order. The following contrasts 

 illustrate the distinction between these two groups : 



1. Alimentation. In animals this system consists of a 

 mouth, stomach, intestine, and digestive glands; food is taken 

 into the body either as a solid or a liquid. In plants the system 

 is poorly developed, consisting of root hairs for taking in liq- 

 uids, and stomata for absorbing gases, but having no digestive 

 organs. The foods absorbed are either liquids or gases, but 

 never solids. 



2. Circulation. In animals circulation is brought about by 

 a heart and blood vessels, or something corresponding to them. 

 In plants the water absorbed from the roots ascends the stem, 

 and passes out into the leaves by a process known as the ascent 

 of sap, and the materials formed in the leaves are dissolved 

 and eventually diffused throughout the plant, passing down- 

 ward in certain of the cells of the stem. There are no real 

 blood vessels, no heart, no blood, and no definite circulation. 



3. Metabolism. In animals metabolism is essentially destruc- 

 tive. The animal uses as food organic compounds like carbo- 



