96 Kansas Academy of Science. 



though they were obeying the word of command of some supervising 

 architect. The inherited blue prints in these cases are followed with 

 few mistakes and no cheating. The egg and sperm cells of adult ani- 

 mals have a specialization no more wonderful than that of the other 

 soma cells. They have their special work to do and accomplish it in 

 accordance with the inherited tendencies of their species. 



The one question of absorbing interest to all students of life, whether 

 plant or animal, is, Who is the supervising architect, and how are his 

 plans executed? Materialistic biologists have attempted to answer this 

 question, but their biogens, biofors, determinants and energy reactions 

 lie peacefully sleeping in the scrap heap of mere hypotheses. 



It is the purpose of this paper to prove by direct evidence, that 

 changes in the habits of animals (and plants as well) are registered 

 slowly but surely in the body-building and body-using instincts of the 

 succeeding generations. 



In the Eocene period of the Tertiary era, as shown by their fossil 

 skeletons, little horses grazed on the tender herbage of the swamps of 

 western Kansas and Nebraska. These horses had four well-developed 

 toes on their fore feet and three toes on their hind feet, all being useful 

 in supporting the animals in the bog-lands. The five-toed ancestors of 

 these Eocene horses have not yet been discovered, but skeletons with 

 the missing first digit will undoubtedly be unearthed in the near future. 



As western Kansas and Nebraska became higher and drier with the 

 upheaval of the Rocky Mountains, Eohippus depended more and more 

 on speed to escape the wolves and fierce cats. In running the little 

 horses used the third digit chiefly, the second and fourth digits some- 

 what, and the fifth digit not at all. Slowly the third digits increased 

 in size, and the fifth digits diminished till they became rudimentary and 

 disappeared. It took one million years, according to Osborn, to lose 

 the fifth digit through disuse. In the Miocene Tertiary all the horse 

 skeletons show but three toes. As the horses became larger and the 

 plains higher and drier, the horses used the third digit more exclusively. 

 The third digits with their nails or hoofs grew in size with use and 

 became the main and finally the only supports of the body. The second 

 and fourth digits diminished in size with disuse and are now rudimentary. 

 These digits are represented in the modern horse by the so-called splint 

 bones, rudiments beneath the skin, of the metacarpal and metatarsal 

 bones of these digits. Two additional million years were required to 

 dispose of these side digits and make the American Quaternary horse 

 an apparently one-toed animal. 



The instinct in the horse for developing five digits on each leg is not 

 entirely lost. According to Professor Wentworth of our Agi-icultural 

 College, himself an authority on animal breeding, Dr. J. Cossar Ewart of 

 Copenhagen says that three toes are found in the embryos of all horses 

 at about the fifth or sixth week. In draft horse embryos vestiges of all 

 five toes, according to Doctor Ewart, persist till the same period. Chest- 

 nuts and ergots on the legs of horses are usually regarded as represent- 

 ing the hoofs of the missing digits. The paleontologist can furnish 

 dozens of examples showing the influence of environment in causing 



i 



