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these investigations into origin stress should be laid, not exclusively on 

 the so-called " determining species " among the weed seeds mixed with 

 the seed, — that is to say, not only on species which occur only in a given 

 provenance and are characteristic thereof, — but regard should also be paid 

 to all " secondary species," i.e., the other less characteristic species. In 

 fact all the characteristics of a seed should be taken into consideration, 

 Sbs these may materially help us in the definition of origin. I, therefore, 

 proposed a comprehensive and thorough examination of the different 

 provenances, based on authentic specimen samples, and intended that 

 the investigation should be confined in the first place to the most 

 important of the seeds, namely, red clover. 

 The investigation should extend to : — ■ 



(a) The seeds of weeds. — It was laid down as essential, that all 

 the different kinds thereof shoiild be accurately ascertained numeri- 

 cally, since indications like ' ' common, " " very frequent, " " frequent ' ' 

 cannot suffice for the determination of the finer distinctions in the 

 weed-flora of the seeds of the different countries. To facilitate this 

 work, I proposed a special system for the examinations, whereby 

 it is made possible to count the raore frequent species in only a 

 small part of the sample. 



(b) The other impurities. — It was recommended that special 

 attention should be paid to the remaining impurities in seeds, since, 

 as was pointed out in the lecture at Copenhagen, it is also possible 

 to arrive at conclusions as to the origin of a seed from the mineral 

 impurities found therein, and it is often possible, as was shown 

 by G. Tryti in particular, to determine the origin by fragments of 

 leaves found in seed. 



(c) The colour. — Here, too, we find differences. We proposed to 

 fix these into five different grades : — ^violet, predominating violet, 

 mixed, predominating yellow and yellow. Thus, only the dis- 

 tribution of the colour was considered, not the tone. To determine 

 the tone of violet and yellow it would have been necessary to use 

 colour standards. The French " Code des couleurs " by Klinksieck 

 and Valette is out of print, and the American " Color Standards " 

 by Ridgway is too little known, besides being out of reach of many 

 stations owing to the present monetary conditions. 



(d) 2%e " Thotcsand grain weight." — This weight-test by itself 

 will never suffice to determine origia of red clover, but, together with 

 other tests, it may strengthen an opinion as to the origin of a seed. 



Special stress was laid upon the necessity of using absolutely authentic 

 seed for the purposes of the investigation. The specimen samples should 

 be obtained exclusively from absolutely reliable sources, and comprise 

 samples already commercially cleaned. In the investigations also those 

 countries should take part which produce red clover for their own 

 consumption only — i.e., those which do not export such seed — as the result 

 of such investigation may help to supplement conclusions as to the 

 geographical distribution of weeds. 



Within a country the different producing districts should be kept 

 separate, if, on examination, appreciable marks of distinction should be 

 found. It was also recommended that records of the different sub-species 

 of red clover (as for instance, common and late flowering red clover) 

 should be kept separately. 



The publication of the results was left to the option of each participant, 

 but it was recommended that a vmiform method of report should be 

 adopted. By this procedure, results become comparable and their 

 utilisation is much facilitated. It was also contemplated that statistics 

 as to the size of the crops of red clover seed in each country and their 

 variations from year to year should be collected. In addition, we should 

 have particulars as to exports and also as to the approximate distribution 

 01 the red clover seed crops in the different growing districts within each 

 country. It was assumed that such information might be obtained by 



