PRINCIPLES OF SEED TESTING 359 



well to quote here a few cases in which expert exami- 

 nation has clearly demonstrated the worthless character 

 of the seed concerned : 



1. At the first International Conference on Seed- 

 testing held at Hamburg in 1906, Dr. Stebler of the 

 Zurich Control Station quoted l a case which, he 

 said, would give an idea of the unclean state of a clover 

 sample. His table shows that in 550 grams (=19.4 

 ozs.) of the sample, no less than 8478 seeds foreign 

 to the sample were present. These seeds represented 

 39 species of plants, the majority being weeds ; there 

 were in fact 4500 seeds of Plantago lanceolata, 2240 of 

 Daucus Carota, 1140 of Cichorium Intybus, 160 of Prunella 

 alba, and 1 5 1 of Cuscuta Trifolii (Clover Dodder). 



2. In the year 1906, 4779 samples of seeds were 

 tested at the Royal Seed Control Station at Vienna, 2 and 

 1273 (=26.6 per cent) were infested with Dodder; 

 996 out of 2789 samples of red clover (Trifolium pra- 

 tense), or 35.5 per cent, were infested. The ten year 

 average shows that 27.4 per cent of the red clover 

 samples have contained Dodder. 



3. Dodder is not so freely found in clover seed in 

 Britain, but it is still too common. In 1905, for 

 example, 1 1 per cent of the clover seed samples ex- 

 amined by the Botanist to the Royal Agricultural 

 Society 3 were condemned owing to the presence of 

 Dodder seeds, two samples of red clover containing 

 as much as 6 per cent. 



4. " In some samples tested in the United States 

 one which contained less than i per cent of impurity 

 had about 3000 weed seeds to the pound ; while in 



1 Verdhandlungen der i. inter national en Konferenz fiir Samenpriifung zu 

 Hamburg vom 10-14 Sept. 1906, p. 15. 



2 Organisation und Ewtwicklung der kaiserl. konigl. Samen- Kontrol 

 Station in Wien vomjahre 1881 bis inkl. 1906, p. 23. 



3 four. R.A S.., 1905, p. 162. 



