THE INBORN POTENTIALITY OF THE CHILD 307 



elements for the preservation of the individual, as the repro- 

 ductive cells are the master cells in the preservation of the 

 species, and they are functionally interdependent. 



LECTURE II 



THE INBORN POTENTIALITY OF THE 



CHILD 



By the inborn potentiality of the child I do not mean altogether 

 what the child is born with, for it might be born with a disease 

 or defect which was really not inherited but due to injury or 

 disease acquired by the developing embryo before birth. Now 

 in order to make the distinction between hereditary conditions 

 and congenital conditions of the child quite clear to you, it is 

 necessary for me to explain some essential facts concerning 

 heredity. 



All the broad facts concerning heredity were known to the 

 ancients, as is clearly shown by the poet and philosopher 

 Lucretius, who in De Rerum Naturce says : " Sometimes, too, 

 the children may spring up like the grandfathers, and often 

 resemble the forms of their grandfathers' fathers, because the 

 parents often keep concealed in their bodies many first be- 

 ginnings mixed in many ways, which, first proceeding from 

 the original stock, one father hands down to the next father ; 

 and then proceeding from these, Venus produces forms after 

 a manifold chance, and repeats not only the features, but the 

 voice and hair of the forefathers ; and the female sex equally 

 springs from the father's, and males go forth equally from the 

 mother's body, since these distinctions no more proceed from 

 the fixed seed of one or other parent than our face and bodies 

 and limbs. Again, we perceive that the mind is begotten 

 along with the body and grows up together with it and grows 

 old along with it." It was the custom, you remember, of 

 noble Romans to carry in their triumphant processions the 

 masks of their ancestors ; consequently many of these facts 

 became apparent to them. 



Of the broad principles of human heredity we know very 

 little more than this ancient philosopher. Science, aided by 

 the microscope, has taught us much concerning the material 



