ANIMALS, MINKKALS, AND PLANTS 



are depemleiit for their very existence upon inorganic sub- 

 stances, and ultimately, wlien life is extinct, they are re- 

 duced to the same inorganic mineral materials from whence 

 tlie}' sprung. 



Notwithstanding the dependence of animals upon min- 

 erals, there is unciuestionably a great difference between 



them. This difference 

 resi( les largely in the fact 

 that animals possess that 

 sulitle and indefinable 

 characteristic called life, 

 wliile minerals do not. 

 On the other hand, the 

 difi'erence that exists be- 

 t\\cen animals and min- 

 erals does not exist 

 between animals and 

 plants; for both of the 

 latter possess life and 

 hence are e\-identl}' much 

 more closely related to 

 each other than to min- 

 erals. In fact, so closely 

 do animals and plants 

 reseml)le each other in some cases, that it is often im- 

 possible to tell them apart. For examjilc, look at the 

 animal and the plant siiown in Figure 1, and note the 

 impossibility of deciding from appearances which is an 

 animal and which is a plant. It is easy enough to 

 tell a horse from a tree, but as we go lower in the 

 scale of hfe, animals and plants become more and more 

 alike in appearance. In fact, it is impossible to o-ive a 



Fig. 1. — -"1, Gorgonia ; C, Fucus. 



