98 



of seed from the United States of North America I have noticed 

 that sphnters of bark, leaves, and parts of stalk, all with a hairy STirface, 

 are characteristic. These plant particles, according to Konservator Dahl, 

 of the Botanical Museum, University of Christiania, come from a 

 species of Solanum, probably Solanum caroKnense L. (the horse nettle). 

 From statements made by the Public Mycologist, Mr. Jorstad, it appears 

 that it may be possible to determine the origin of the seed fairly accurately 

 if only one can identify the hairy plant particles contained in the sample. 

 Some splinters have stellated hairs and thorns, others have single hairs. 

 The splinters with stellated hairs are found particularly in poa and 

 agrostis seed, and splinters with single^ hairs especially in phleum and 

 f estuoa seed. The portions of the plants in qiiestion are an unusually sure 

 sign of identification of seed from the United States of America, but it is 

 in the first place necessary to be able to recognise the splinters. 



2. The Weed Flora. 



In co-operation with Mr. P. A. 0yen, the Glacial Geologist, I have 

 found that, even if a sample does not contain characteristic seed, in the 

 old sense of the word, the weed flora as a whole will give a good idea 

 as to the origin of the seed. In short, Norwegian seeds give one "floral 

 picture," seeds of the southern part of Sweden (Scania) give another, 

 German seeds give yet another, and so on. I am sure that this method 

 will be of the greatest importance. The weed flora is like the species of 

 animals, biologically localised. By this method it is not only possible 

 to say if the seed is Norwegian, but also from which part of Norway 

 it comes. 



3. The Mineral Impurities in a Sample. 



In the autumn of 1922, Mr. P. A. 0yen, the Glacial Geologist of the 

 University of Christiania, delivered a course of lectures on the deposits 

 of the Glacial period in Northern Europe, £uid in these lectures he main- 

 tained that Norwegian arenaceous quartz is different from that of Central 

 Europe. Later on Mr. Heggenhougen, the Public Chemist, said that 

 Central European quartzose has eolian marks and that the sand in Central 

 Europe was eolian-drift sand. I have since carried out work in the same 

 direction. The quartzose sand-grains in the German Loess soil, in the 

 sand from the Lunebxu-ger heath, in the Danish sand, and even in the 

 sand from the Sahara, are rounded with a wind-Worn surface, dotted, 

 scarred, carved, and with a dull lustre. Norwegian sand, the sand of 

 North Sweden and of Finland, and Canadian sand has a sharp-edged 

 grain, and is a deposit of rivers and seas. About 30 years ago Professor 

 Bastian Larsen pointed out that seed containing Silurian sand must be 

 regarded as seed grown in the district about Lake Mjosen. Norwegian and 

 Scandinavian Seed Control Stations, however, had no idea that quartz 

 sand might be of importance in deciding as to the origin of seed until 

 Mr. 0yen, in his lectures, brought this truth home to us. By ascertaining 

 the type of sand, its appearance, colour and surface, and by examining the 

 particles of earth in the sample, one gets the " mineral picture " of the 

 sample ; and, just as the flora varies in different arable lands, so also the 

 Boil is variable. I am of the same opinion on this matter as Mr. P. A. 0yen, 

 and I am most grateful to him for all he has done to help Norwegian seed 

 control and Norwegian agriculture. Finally, I should like to add that 

 in seed of American origia, as, for instance, timothy, a quantity of excre- 

 ments is sometimes found which, among others mentioned above, 

 especially characterise American seed. I am unable to suggest by what 

 animals these black bodies are excreted. 



Mr. Dorph-Petersen referred to the fact that his station at 

 Copenhagen had taken part in these provenance investigations, 

 and stated that he also had found plant and mineralogical 



