124 Kansas Academy of Science. 



body which are vestigial. On the other hand, our ancestors 

 have used various parts and organs to an increasingly greater 

 extent than the same parts and organs were used by our still 

 more remote progenitors, with the result, as it is hoped this 

 paper will show, that the parts and organs appear in the fol- 

 lowing generations down to man of the present time with more 

 and more complex structures and greatly increased functions, 

 all because the life-powers are educable. 



The most primitive of all organs in the bodies of animals is 

 the digestive cavity. This statement is supported by the em- 

 bryologist, the evolutionist, and, in a somewhat indirect way, 

 by the paleontologist. 



The embryologist finds that the fertilized eggs of all metazoa 

 become in succession morulas, blastulas, simple gastrulas, and 

 complex gastrulas, as they develop. This in itself would not 

 be especially interesting had not the embryologist discovered 

 that these stages of development of the embryo possess coun- 

 terparts in a series of adult animals of lower classification. 

 Thus he finds the following corresponding forms : 



Fertilized egg Hematococcus. 



Morula Pandorina and eudorina. 



Blastula Volvox. 



Simple gastrula Fresh-water hydra. 



Complex gastrula Worm, amphibian, reptile (Therio- 



donts), lower mammal, man. 



The evolutionist explains this remarkable series of corre- 

 sponding structures by calling attention to the fact shovvn in 

 geology that the lower forms of life appeared on earth first, 

 and then successively higher forms, such as : Protozoa, coslen- 

 terates, worms, fish, amphibians, reptiles, lower mammals, 

 and, lastly, man. The law of development he has found to be 

 such that only one in a million of each species develops struc- 

 tural characteristics of higher importance, while the other 

 999,999 have remained like their ancestors. The descendants 

 of these stay-behinds remain on earth to-day little changed, 

 except in minor details of structure, and thus serve to show 

 to the evolutionist what his ancestors have been back to the 

 beginning. 



In this list of ancestors we find that the sponges and coelen- 

 terates were the first to take the gastrula form, and thus were 

 the first to possess a true digestive cavity. The paleontologist 

 finds by a study of the fossils of the earth's crust that sponges 

 and coelenterates were common in the Cambrian era, but with 



