PLANT-BREEDING 1761 



as sickty and healthy leaves from the same so^^bean plant, showed respect- 

 ively. 1. 1 1 per cent of magnesium as against 0.88 per cent magnesium. 



All varieties of the seed used contained more magnesium than calcium, 

 while ordinarily the remainder of the plant contained more calcium than ma- 

 gnesium. 



Nitrogen was applied to the legumes as well as to the cereals, so as to 

 be sure that this was not the limiting factor. 



Conclusions. — i) Wheat, soybeans, alfalfa, and cowpeas grew normally 

 either in 96 per cent of dolomite and 4 per cent sand, 100 per cent of magne- 

 sian limestone, or in sand containing 7 per cent of magnesite. 



2) Dolomite up to 40 per cent proved beneficial to plant growth. These 

 results indicate that dolomite and magnesian limestone will not be detrimen- 

 tal as applied in agricultural practice. 



3) Applications of prepared magnesian carbonate up to 0.7 per cent 

 caused no injury in brown silt loam, but 0.35 per cent prevented the growth 

 of all plants tested in sand. 



4) The crop yields and the ratio of calcium to magnesium within ra- 

 ther wide limits produced no marked differences in yields. 



5) Different ratios of calcium to magnesium within rather wide 

 limits produced no marked differences in yields. 



6) Increasing the size of applications increased the calcium and magne- 

 sium content of plants. 



7) A tolerance of calcium and magnesium occurred in all varieties 

 of plants grown. With approximately identical yields, wheat straw grown 

 in sand, brown silt loam, dolomite, and soil containing 35 per cetit of magnesite 

 showed calcium contents varying between O.165 per cent and 0.547 P^^" 

 cent and magnesium contents varying between 0.132 per cent and 0.955 per 

 cent. 



8) Acid extractions failed to remove all the calcium and magnesium 

 from the sand. There remained after the various extractions from 768 to 

 852 mgms. of calcium and from 540 to 960 mgms. of magnesium per 6000 

 gms. of sand. 



9) The plants possessed a decided abilit}- to obtain calcium and magne- 

 sium from sand extracted with strong hydrochloric acid, as borne out by 

 the following example : Three crops of alfalfa removed from acid extracted 

 sand 164.43 mgms. more calcium, and 90.4 mgms. more magnesium than 

 was contained in seeds similar to those planted. 



1272 - Etiolated Cereal Plants. — Kalt B.,in Zcitschiift fur Pflanzenzuchtunn, \'(>1. 4. No. z. 

 pp. 143-150. Berlin, June 1916. 



■Many references have been recently made to the a^jpearance of etiolated 

 plants and the present paper describes some investigations made in 1915 at 

 the Agricultural Institute of Halle Uni\'ersity, Germany. 



I. Barley. — A plant of a pure line of Groninger Wintergerste was cross 

 ed in 1915 with pollen from a pedigree plant of original Eckendorfer Mam- 

 mut-Wintergerste. The F^ generation gave about 30 perfectly normal plants 

 from which 26 were chosen for pro]:)agation The descendants of 25 of these 

 plants were quite normal in appearance, but from the last one (Elite ^/j^) 



