78 



THE MONTHLY BULLETIN. 



commissioner for distribution or direct to the growers theinselves, 

 according to the wishes of the individual commissioners. This will 

 avoid much w^aste, as it enables the commissioners to investigate the 

 requests and to ascertain whether or not there is a real necessity for the 

 colony. Unfortunately, a few growers apply for the ladybirds when 

 they have no need for them, merely because they are furnished free of 

 charge. In this way many are wasted, and as the supply is never equal 

 to the demand, many growers who have a real reason for asking for the 

 insects are unable to obtain them. This we believe can be remedied to 

 a considerable extent by having all applications come through the horti- 

 cultural commissioners of their respective counties.— Harry S. Smith. 



THE CALTROP OR GROUND BUR-NUT. 



(Tribulus terrestris.) 



The ground bur-nut was first sent to the Commission of Horticulture 

 by Mr. K. S. Knowlton, Horticultural Commissioner of Kern County, 



Fig. 2 0. — The caltrop or ground bur-nut, showing the 

 seed burs and leaves. (Photo by Leroy Childs. ) 



September 3, 1912. At that time Mr. Knowlton stated that the weed 

 was scattered to some extent in the immediate vicinity of Bakersfield, 

 growing along the sides of the streets and on vacant lots. The speci- 

 mens were forwarded to Prof. H. M. Hall of the University of Cali- 



