rye; pr„\cticums 355 



Chnsiian era. The origin of its cultivation is supposed to be 

 northeastern Europe. 



Within modern times rye \vas fomierly a more important 

 crop. Even as late as the middle of the nineteenth century rye 

 was said to have fonned the principal sustenance of at least 

 one-third the population of Europe, barley taking its place in 

 countries nearer the Mediterranean. It was annually sown 

 with wheat, and is yet to a large extent mixed with wheat in 

 grinding, and the resulting flour is called meslin. The mixture 

 of maize and y\q for bread was common in New England. 

 Relatively, r}-e was formerly much more important in England 

 and the United States. 



Practicums. 



499. IXFLUEXCE OF SPECIFIC GR-WHTY UpON GERMINATION. — Make up 



three solutions of sodium nitrate with a specific gravitj' of 1.20, 1.26 and 1.32, using 

 a hydrometer to determine the specific g^a^ity. Solutions may be placed in oat- 

 meal dishes. Take preferably a sample of r}-e of rather low grade and divide into 

 small, medium and large sized grains, either by hand or by means of sieves. (433) 

 Then di\'ide each sample into four groups according to specific gra^•it\•, by placing 

 the sample in the solution of highest specific gra\'ity ; then put that which floats in 

 the solution of next highest specific gravity, and so on. Grains can be conveniently 

 removed from the solution by using a piece of wire gauze. Place fifty seeds of each 

 of the twelve groups thus obtained in germinator at 70° F. and determine the num- 

 ber germinating in 24 hours . • ; 4S hours . . . ; 72 hours . . . : q6 

 hours . . . ; 120 hours . . . (475) Seeds may also be grown as in (433). 

 Wheat and barley may also be treated in the same solutions, and many other agri- 

 cultural seeds may be tested by varying the density of the solutions. A saturated 

 solution of common salt and a saturated solution of ammonium nitrate made by 

 boiling will upon cooling to 75° F. have a specific gra%'ity of approximately 1.20 and 

 1.30 respectively. For further details, see N. Y. (Geneva) BuL 85& 



500. Study of Plant. — Examination under Nos. i to S preferably mada in 

 field : Nos. 9 to 16, in the laboratory. 



1. Height of culm : average of ten culms to tip ot upper beard . . . 



2. Diameter below spike: average of ten culms . . . 



3. Wall of culm (compared with wheat) : thick; medium ; thin. 



4. Foliage (compared with wheat): scanty; medium; abundant. 



5. Rust: leaves, per cent . . ; culms, per cent . . . 



6. Ergot : per cent . . . 



7. Spike . erect ; leaning ; nodding. 



