ox THE " SALT WATER SELECTION " METHOD OF SEEDS. 423 



There is still another question which has not yet been investi- 

 gated, and to which no author has yet jjiven an answer ; — in what 

 ratio should the various constituents, mineral matter, albuminoids. 

 carboh}'drates, be contained in the best seed ? Or is there no rule 

 as to their relative quantities to determine the quality of a seed ? 

 At least within certain limit, there must certainly be some rule in 

 this matter, and I am inclined to think that here also that " Law of 

 minimum " holds true. As this important question has not yet been 

 answered — nor likely that it could be answered easily — the question 

 of the quality of seed can be answered safely only by direct ex- 

 periments. 



Many investigations have been made on the quality of seeds in 

 relation to their specific gravity. The experiments of F. Haber- 

 landt, Church, C. Trommer, H. Haberlandt, Th. Dietrich and many 

 others besides myself have all given similar results and have gone 

 to prove that those seeds whicli l^ive a higher specific gravity are 

 more productive. These experimenters, however, have all fallen 

 into the same mistake, viz. that of sorting their seeds according to 

 their specific gravity regardless of their weiglit, — a mistake which 

 has detracted much from the value of their experiments and has 

 entailed unreliable results for ascertaining the quality of seeds. 



It seems that H. Hellriegel was the first who found out this 

 mistake and renewed his experiment, the results of which are given 

 in his " Beitriige zu den naturwissenschaftlichen Grundlagen des 

 Ackerbaus." From his results, it may be seen that specific gravity 

 by itself, when seeds of similar weight be selected according to their 

 specific gravity, has no regular relation with the quantity of produce 

 obtained with the seeds. Similar results have been obtained by K. 

 Wollny conducted on a larger scale in the field. 



Experiments were conducted in i<S94 by H. Ando, a student of 

 our College. He selected barley seeds of similar specific gravity 

 with a solution of sodium bromide, and from the selected seeds, he 

 took 14 grains all of nearly the same weight. They were sown in 

 Wagner's cylinder, filled with garden loam, 7 grains in each cylinder 

 making 4 series in all and ascertained the length of the stalks and 

 leaves developed in a week. The result was as follows : — 



(4) Snnt uiiil I'flci^e dcr l.Tiulwirth Kulturpd.mzcn. Ufrliii 1885. 



