Lecture XXIX. 269 



PRACTICAL WORK. 



Evidently breeding experiments are impossible in a short elementary course, 

 so that we will have to content ourselves by becoming familiar with one or 

 two classical examples of unit characters. 



Select out of a mixture of edible pea seeds some which are angular (quad- 

 rate) and some which are round. If such a mixture is placed on a smooth 

 piece of board and the latter is slightly inclined gentle shaking will make the 

 round peas run down the slope leaving the angular ones in position on the 

 board. 



From a similar mixture select green and yellow coloured peas. By re- 

 moving the seed- coat of some of the peas notice that the colour of the 

 cotyledons of the embryo may be concealed by that of the coat. It may be 

 recalled that the coat and the cotyledons belong to different generations. 



Write down the possible offspring of a round yellow pea of unknown origin 

 when selfed. 



What offspring may be produced by plants grown from each of the follow- 

 ing when selfed : round green, angular yellow and angular green peas ? 



What offspring would you expect from a plant grown from a round green 

 pea when pollinated by one grown from an angular green pea ? 



