30 



THE FARMER'S MAGAZINE. 



ences of weight l>etween larj^e and small roots are 

 very rarely accompanied by equal difl'erences be- 

 tween the amounts of solid matter ; and this is 

 not only true of all roots compared together, but 

 even in many cases of roots grown in the same 

 field under, as nearly as possible, similar condi- 

 tions, as we shall see presently. To give a few 

 examples from the table : — 



The greatest observed diflference of solid matter 

 (10.81) is attended by a difference of weight of 

 only 2lbs. Sjoz., while the greatest difference of 

 weight observed between two roots grown together 

 (lOlbs. 4oz.) shows a difference in percentage of 

 sohd matter of only 2.40. A nearly equal differ- 

 ence of weight in another case (9lbs. 15ioz.) gave 

 a difference of sohd matter of only 0.17 per cent. 

 To what are we to attribute these extraordinary 

 variations ? If the experiments had been limited 

 to a few specimens, they would be set down, most 

 probably, to the action of the soil and manure ; 

 and no doubt both causes may have contributed 

 to the result. But as similar variations, and 

 sometimes lo as great an extent, may be observed 

 among roots grown under precisely the same con- 

 ditions as to soil and manure, it is evident that an 

 initial cause of difference must have existed in the 

 germs from which they were produced. I was led 

 to this opinion by observing that roots grown 

 from inferior, and especially from mixed seeds, 

 but nnder precisely similar conditions as to soil 

 and manure, varied very much in their composi- 

 tion, and did not follow exactly the law of size; 

 while good, uniform, and fully ripened seed in- 

 variably followed that law. The following examples 

 will illustrate this ; — 

 I, — White Silesian beel, grown upon a strong clay 



soil, and manured with matter from cesspools 



and sulphate of ammonia. 



MIXED IXFEUIOU SEED. 



Percentage of 

 Weight of Root. Solid Matter- 



13 lbs. 4 oz 8.73 



12 „ 7i „ 6.43 



10 „ 5 „ 9.75 



8 „ Hi „ 9.92 



5 „ 13i „ 7.52 



3 „ „ 12.74 



2 „ 10.^ „ 10.42 



1 ,, 12j „ 10.42 



GOOD UNll'OUM SEED. 



Percentage of 

 Weight of Root. Solid Matter. 



7 lbs. lO.H oz 11.9-1 



6 „ 12:5 „ 12.32 



6 „ 64 „ .• . . . . 12.80 



6 „ 2i „ 13.09 



4 „ .3j „ 14.32 



2 „ 6^ 16.02 



2 „ 12^ „ 14.56 



1 „ 15f „ 15.48 I 



II. — Long red mangel-wurtzel grown on a light 

 clay soil, and manured with farmyard manure. 



MIXED INFERIOR SEED. 



Percentage of 

 Solid Matter. 

 . 12.92 

 . 6.94 

 . 12.49 

 . 16.33 

 . 15.99 

 . 14.30 



GOOD UNIFORM SEED. 



Percentage of 

 Solid Matter. 

 . 12.84 

 . 13.03 

 . 15.20 

 . 14.80 

 . 15.86 

 . 16.96 



It would appear, howcver, that, although the 

 initial cause of variation from the law of size is 

 resident in the germ, the soil and manure may 

 increase or diminish the amount of divergence. 



The ordinary seed used by husbandmen is rarely 

 the seed of ])lants grown upon the same kind of 

 soil and with the same kind of manure, that is, 

 under more or less analogous conditions, but 

 rather a mixture of seeds from different localities 

 and produced under the most various circum- 

 stances. If then, there be really an initial cause of 

 difference resident in the germ, we have a sufficient 

 explanation of the difference which any one may 

 observe between the quality of roots grown in the 

 same field. Nov/ an important question suggests 

 itself, namely, is the initial cause of difference in 

 seeds hereditary, or in other words, is it derived 

 from the peculiar qualities of the plants which 

 bore it? If this be so, the seed of each plant 

 must transmit more or less of its individual quali- 

 ties, as well as the specific ones, to the plants 

 which they will produce, subject to the modifying 

 influences of soil, manures, climate, &c. 



One of the most striking differences in quality, 

 which roots exhibit, is that of relative amount of 

 solid matter — a difference which may be deter- 

 mined by ascertaining their specific gravity; the 

 roots containing least water being densest. I 

 therefore determined to try whether this property 

 of density could be propagated. For this purpose 

 I selected three roots of white Silesian beet of 

 nearly the same size (2lbs. 6oz. to 2lbs. 7oz.), but 

 exhibiting as great a difference in specific gravity 

 as possible. I determined the specific gravities by 

 means of a series of solutions of common salt, 

 indicating differences of specific gravity equal to 

 0.005. I employed eleven solutions placed in 

 wide-mouthed jars, numbered from one to eleven. 



