132 The (JrtHriiitj of Ltnstol In Enylaiul 



In tliis case, however, the crops were fjrowii on farms which produced 

 poor quality linseed only and hence the conditions were ail in favour of 

 a decrease in oil content. 



U]i to the present we have not had the opportmiity of testing this 

 in many cases, but a few data have been obtained with I'skoif and 

 Plate seed grown for several successive generations in different parts of 

 England. 



The results are given in Table IV. 



Table IV. 



Pskoffseed. Iinpoitccl liHl 37-45 % oU 



„ Grown Wiiiihlodon (1912) from 1011 imported .sc-cd . . 35-66 



Grown Wyi! (liUa) from Wimlilcdim 1II12 seed .. .. 33-21 



Grown Wye (1914) from Wve 1913 Wiml)l.-ilon 1912 seed 33-.35 



Grown Wye (1913) from imported (1911) seed .. .. 34-05 



Gro\vn Wye (1914) from Wvr 1913 .«eed 34-96 



Grown Wve (1914) from imported (191 1) see<l . . . . 33-78 



Grown 8eiby (1913) from imported (1912) seed .. .. 36-68 



Grown Selby (1914) from Selby( 1913) seed .. .. 35-05 



Plate seed. Imported (1912) 38-45 



„ Grown Wve (1913) from imported (1912) seed . . . . 42-82 



Grown Wve (1914) from Wve (1913) seed 41-64 



Grown Wye (1914) from Wported (1913) seed 3910 



It will be seen that in some instances a diminution in oil content 

 does occur from generation to generation and there are indications that 

 the percentage of oil produced eventually becomes more or less constant. 

 On the other hand such diminution might conceivably be due to seasonal 

 and cultural variations or to variations in soil factors from year to year. 



Such effects could be eliminated by growing parent, child, grandchild, 

 and great-grandchild etc. seed during the same season and on the same 

 plots. This has been done in one or two instances and as shown in the 

 table the variations then disappear; practically no difference in oil 

 content being exhibited by the various generations when grown side 

 by side in the same season and under identical conditions of soil and 

 cultivation. 



At any rate our results give no support to the view that repeated 

 growth of linseed from the same stock gives rise to a seed of diminished 

 oil content. 



The effect of artificial manure!< on the oil content. 



The use of artificial manures has been found to occasion only a very 

 slight variation in the oil content of linseed. This conclusion is based 

 upon the results of trials carried out with Dutch seeds at Rothamsted 

 during the hot season of 1911 and at Holmes Chapel Agricultural 



