HISTORY AND BIBLIOGRAPHY 831 



F. H. Hillman. Dr. E. Zeeuw has published the results on the 

 comparative viability of seeds, fungi, and bacteria, when subjected 

 to various chemical agents. Ernest Bessey gives the results of seed 

 analysis for 1911 and 1912 from which it appears that buckhorn 

 and plantain were frequent. The paper gives the number of weed 

 seeds in a pound. 



Mr. Parsons in 1893 made some interesting tabulations in a 

 summary of American seed vitality tests. In the results offered 

 by him we find the following : Alsike 72.7 per cent, crimson clover 

 59 per cent, red clover 84.8 per cent, mammoth clover 82.5 per 

 cent, white clover 72.1 per cent, alfalfa 61.6 per cent. 



Pennsylvania. — ^Prof. Butz studied many hundreds of samples 

 of seeds, chiefly with respect to their germinative power. In many 

 cases the percentage of germination was very low. Thus we find 

 recorded the following : Alfalfa 52 per cent, alsike clover 61 per 

 cent, Japan clover 69 per cent and seradella 13 per cent. 



Ohio. — Mr. Devol early recognized and emphasized the im- 

 portance of the experiment station in studying the viability of 

 seeds. In tests conducted by him clover showed a germination of 

 93 per cent. 



Later Selby and Hicks made a study of fifty-two samples of 

 clover and alfalfa seeds sold in Ohio. They found not only that 

 the seeds had a low vitality but that they contained considerable 

 impurities. 



Nevada.^Several very important papers have been published 

 by Mr. Hillman on clover seeds and their impurities. One of his 

 earlier bulletins deals with the descriptions of weed seeds and their 

 distribution, together with an incidental account of.the occurrence 

 of these seeds in commerce. In a later publication he considers 

 the weed seeds found as impurities in various types of seeds, in- 

 cluding alfalfa, red clover, white clover, alsike clover, crimson 

 clover, Japan clover, Bokhara clover, yellow trefoil and esparcette. 

 In his investigations a large number of samples was examined. 

 The paper therefore gives a fair estimate of the impurities gen- 

 erally found in the various clover seeds offered for sale in this 

 country. 



Kansas.- — Prof. Roberts and Mr. Freeman carried on an extensive 

 investigation of alfalfa seed, showing adulteration, substitutes 

 and impurities; and the methods of detecting the latter. They 

 found some adulteration in alfalfa seed. The yellow trefoil 

 {Medicago ' lupulina) was most frequent though there were occa- 



