SEVEN PRINCIPAL LAWS OF HEREDITY. 231 



fore, this morning I am to draw before you a dark 

 picture, I must put by the side of it a bright one. 

 The left hand and the right hand in the government 

 of the universe are contrasted as are the antipodes 

 of the world ; but even antipodes are parts of one 

 circle. Possibly we shall find that, after all, the right 

 and left hand of the laws of hereditary descent are 

 adapted to each other, may easily be clasped the one 

 upon the other, and that behind the two hands is 

 only one form and one heart, and that Almighty 

 God's. The descent of bad traits may be a blessing, 

 although one of another sort than the descent of 

 good traits. It is evident that the two laws operate 

 together under the control of one almighty purpose, 

 — that of moulding humanity into — it does not yet 

 appear what, but into something like its Author. 

 [Applause.] 



I am accustomed to summarize the laws of heredi- 

 tary descent under seven heads, — direct heredity, 

 reversional heredity, collateral heredity, co-equal 

 heredity, pre-marital heredity, pre-natal heredity, and 

 initial heredity. 



1. By direct heredity is meant the usual action of 

 the laws of descent. The child resembles its parents ; 

 and yet, as Ribot has said, we must distinguish under 

 this head two different sets of facts. In the first 

 place, a child may resemble both its parents equally ; 

 in the next place, it may resemble one of them pecu- 

 liarly; but in that second class we must distinguish 

 two sub-classes, — the likeness may be in the same 

 sex, .or not; that is, the son may resemble the father 



