172 LUTHER BURBANK 



second generation in any fixed proportion of the 

 progeny. 



It will probably be found that the condition 

 that leads to the production of perfume of a 

 particular type is so complex and itself de- 

 pendent upon so many factors that it is not 

 inherited in any simple and readily traceable 

 relation, and the practical results fully carry 

 out this view. 



One of the distant relatives of the fragrant 

 verbena is a fine shrub known as Aloysia citrio- 

 dora. Another, as different as possible in ap- 

 pearance, is a little trailing plant known as 

 Lippia repens. 



This little trailing plant is very valuable as a 

 substitute for lawn grass. It requires less than 

 one-tenth the water required by blue grass, and 

 only a fraction of the care. It need be mown 

 only once or twice in a season, and throughout 

 the summer it will cover the lawn with a dense 

 foliage, and bear a mass of small blossoms 

 resembling those of white clover and fully as 

 attractive to the bees. 



Unfortunately the lippia is not very hardy, 

 and when the temperature goes much below freez- 

 ing it turns to a brownish color. It is not adapted 

 to the cold climates of the northern United 

 States. 



