6 ANIMAL FORMS 



its death should leave offspring to take the place of the 

 parent when it falls from the ranks. This is effected in 

 various ways. In some of the simpler animals the body 

 may divide into two equal parts, each of which becomes a 

 complete individual. In other cases the animal detaches 

 a relatively small portion of its body, much as a gardener 

 cuts a slip from a plant, and this likewise develops into a 

 new organism. In the greater number of animals, very 

 clearly illustrated by the birds, eggs are produced which 

 under favorable conditions develop into an organism resem- 

 bling the parents. 



6. Summary. Animals are thus seen to lead active, busy 

 lives, collecting food, avoiding enemies, and producing and 

 and caring for their young. While the activities of all 

 animals are directed to their own preservation and to the 

 multiplication of their kind, these processes are carried on 

 in the most diverse ways. The manner in which an organ 

 or an organism is made, and the method by which it does 

 its work, are mutually dependent one on the other. As 

 there is an enormous number of species of animals, each 

 differently constructed, there is, accordingly, a very great 

 variety of habits. As we shall see, the lower forms are 

 remarkably simple in their construction, and their mode of 

 existence is correspondingly simple. In the higher types 

 a much greater complexity exists, and their activities are 

 more varied and are characterized by a high degree of elabo- 

 ration. In every case, the animal, whether high or low, is 

 fitted for some particular haunt, where it may perform its 

 work in its own special way and may lead a successful life 

 of its own characteristic type. 



