Man in the Light of Evolution 



cavity Is the stomach or digestive system. A 

 little mass of cells on the outside of the animal 

 forms the reproductive organ. Rude muscular 

 fibrils occur. The beginnings of a nervous sys- 

 tem are seen in the shape of a cobweb of cells 

 and fibers encompassing the body between the 

 two layers. 



The coelenterate has only two organs which 

 are even fairly well developed, those of digestion 

 and of reproduction. The animal lives for these 

 two functions. They are absolutely essential. 

 The digestive system furnishes the material for 

 growth, for the support and all needs of the 

 body. Reproduction insures the survival of the 

 species and the possibility of progress. Appar- 

 ently very little has been attained. Let us not 

 despise the day of small things. The absolutely 

 essential organs have been shaped and tissues 

 have arisen. There is the promise of better 

 things. 



The third stage is of vast extent, and includes 

 all animals from worms to the highest apes. 

 We might call It the animal stage to distinguish 

 It from the almost vegetative zoophytic stage 

 which preceded it. We can easily divide It into 

 several substages, whose members live on very 



26 



