24 



ing the number of samples of seeds in which each kind of weed was 

 found. Thus, in one hundred and forty-eight samples of seeds sold iu 

 Delaware, forty-four contained plantain [Plcmtago major) ; twenty- 

 seven, sheep sorrel [Riunex acetosella) ; twenty-five, rag weed {Ambrosia 

 ■artemisiccfolia) ] five, dodder (Ciisctita) ', and one, Canada thistle {Cnicus 

 urvensis). Twenty-six different species of weeds were found in the 

 samples tested. 



"This list tells its own story, as to how the majority of weed seeds get 

 upon the farm ; for not only is the farmer sowing them, but, as Ledoux 

 has remarked, he is sowing them upon well prepared land, where they 

 will be sure to grow.'- 



Quantity- of imjMrities. — One sample of red clover seed contained 9.2 

 per cent of impurities. These were seeds of nine kinds of weeds, etc., 

 among which were plantain, smart weed, rag weed, and foxtail grass. Tak- 

 ing 8 poundsof this clover seed, the usual quantity for an acre, the number 

 of weed seeds was sufficient to give one seed of sheep sorrel every 4 feet 

 in drills 3 feet apart ; one of rag weed every 10 feet in drills 6 feet apart ; 

 the same number of dodder and enough of all the weed seeds of differ- 

 ent kinds to make one seed every 6 inches iu drills 9 inches apart. This, 

 however, was rather an extreme case. Another sample of red clover, 

 which came nearer the average, bad 1.2 per cent of impurities by 

 weight. If 8 pounds of this seed were sown on an acre, the number of 

 w'eed seeds would be sufficient for one every foot in drills 15 inches 

 apart. 



"The tables show how it is possible, even by the use of a compara- 

 tively iiure seed, to introduce upon laud a supply -of weeds which may, 

 in time, overrun a farm to a serious degree ; and when we consider that 

 this process of sowing weed seeds is repeated from year to year, the 

 argument has still greater force." 



Dodder. — An account of the dodder {Cuscuta trifoUi) is given. This 

 parasite, which grows upon clover, alfalfa, etc., is iu some cases a very 

 serious pest. 



" Every precaution is to be taken against the introduction of this para- 

 site into the State. In Germany its presence has proved a national 

 calamity and well nigh forced German farmers to abandon the growth 

 of clover. 



The flax dodder, according to Ledoux, broke up the culture of flax in 

 Korth Carolina, and paved the way to cotton culture. In Germany, the 

 fight against the Cuscuta has been vigorous, but the enforcement of 

 stringent laws and the sharp eye kept by the German seed-controls over 

 the quality of clover and alfalfa seed, has done much to reduce this evil." 



A striking instance of the need of precautions in this country is given 

 in a sample of alfalfa seed sent to the Station for examination. " The pur- 

 chaser remarked that it was one of the purest seeds he had ever seen, and 

 an examination i)roved this fact, the percentage of impurities being 

 only .42, mainly dirt. But a close examination revealed the presence 



