INTERPRETATION OF FACTS 159 



matin, which breaks up and divides, and is carried on from parent to 

 offspring. These little broken pieces of chromatin are called chromo- 

 somes. The chromosomes have come to be considered the most impor- 

 tant factors throwing light on the many problems of inheritance that 

 is, on all problems that pertain to what we actually obtain from our par- 

 ents, whether these be physical, emotional, or intellectual. 



It is therefore of decided importance that we obtain a clear concep- 

 tion of chromosomes, because in the final analysis every detail of wtiat 

 we are and can be, that has any relation whatever to our physical, emo- 

 tional, and mental makeup must come from our parents through the 

 chromosomes in the egg-cell of the mother and the sperm-cell of the 

 father. In other words, the chromosomes that were ours at the moment 

 of mixture of sperm and egg, possessed the sum total of all the .actual 

 physical, mental, and emotional endowment with which we were pos- 

 sessed when ushered into the world (except food and environment 

 needed for growth, as well as a place to grow). 



In the case of Paramoecia the animal does not inherit anything from 

 its parent it is half of its parent. Each Paramoecium is thus equivalent 

 to an egg-cell or a sperm-cell, though there is no sex present in Para- 

 moecia. The offspring is not a chip from the old block it is half the 

 block. 



An interesting application follows. 



In every living thing where observation of chromosome material 

 lias been possible, life begins from an egg-cell of some kind, and in the 

 higher forms this egg-cell receives one-half the chromosomes from the 

 sperm after the egg-cell itself has cast out one-half of its own chromo- 

 somes. There is thus a constant trend toward forming an average in- 

 dividual of 'the species to which each such individual belongs, for, each 

 new living thing that comes into being is made up of one-half the chro- 

 mosomes \vhich the maternal egg-cell possessed, and one-half of those 

 which the paternal sperm-cell contained. 



If this were not so, then in those cases in the animal world where 

 we have virgin-birth, there would be an ever lessening quantity of the 

 chromosome material in each next generation, so that each offspring 

 would become more and more unlike its parent, until in time, when no 

 fertilization takes place to restore the proper quantity of chromosome 

 material by a paternal sperm-cell being added to the maternal egg-cell, 

 the offspring would not be recognized as a member of the species to 

 \vhich its ancestors belonged. 



Every female at the time of her birth has every egg in her body that 

 she will ever have. This is as true of a bird as of a human being. In 

 the human there are about 35,000 eggs in each of the two ovaries, though 

 only about 100 to 200 of these -actually ripen and pass out of the body 

 during the sexual life of the individual. This means that the mother ha 



