Live Stock Breeders' Association. 87 



is even now, in some of our leading colleges, one of the most im- 

 portant and most popular biological courses. 



The discoveries in this domain during the past decade are 

 nothing less than epoch making. We do not even yet appreciate 

 their full importance, yet important applications of this new 

 knowledge have already been made in the improvement of crops 

 and domesticated animals. 



During the last two years of the past century, five men, 

 v/orking independently of each other, discovered three highly im- 

 portant principles, or laws, which enable us to predict the results 

 of the crossing of two distinct varieties for the second and later 

 generations of the progeny. The discovery of these laws was 

 hailed with much enthusiasm, as it was the first inkling we had had 

 that there are any laws governing the transmission of hereditary 

 character from one generation tx) the next. 



After the discovery was announced, Correns, one of the men 

 who had made the discovery, in searching through the literature 

 of the subject to see whether the law had been recognized previ- 

 ously, called attention to the fact, then not generally known, that 

 these laws had been worked out in very great completeness, by 

 a monk in an Austrian monastery, and published in 1865, and they 

 have very appropriately been named "Mendel's Laws," for this 

 was the name of the recluse who, working with varieties of the 

 common garden pea, had made discoveries which enable us now, 

 I am tempted to say, to produce almost any type of plant or animal 

 we desire, provided we can find the characters we want scattered 

 amongst races or varieties that can be crossed with each other. 

 There are, however, many limitations in the application of these 

 laws, but new facts are being discovered concerning them almost 

 daily. We do not know that all hereditary characters obey Mendel's 

 laws, but many hundreds of them do, and it is barely possible that 

 all do. The highly significant fact is that we have discovered laws 

 v/hich hundreds of hereditary characters do obey. It is now my 

 task to give an exposition of these laws, together with some of 

 the important results which have followed their application in the 

 breeding of plants and animals. 



Suppose we cross a bearded wheat with a smooth (beardless) 

 wheat. (Fig. 1.) Experience shows that this gives a wheat which 

 is smooth, or only very slightly bearded. In this cross we bring 

 together two naturally antagonistic characters. For some reason 

 one member of this pair of characters prevents the other from de- 

 veloping. The biologist expresses this fact by saying that smooth- 



