636 



FARM SEEDS 



GENERAL 



Fig. 192.- 



-Transverse section of good 

 barley grain. 



Fig. 193. — Same of poor one from 



The transverse section of a good barley grain (Fig. 192) is more 

 oval than that of a poor one (Fig. 

 193), the angles corresponding to 

 the nerves of the flowering glume 

 are less marked, and the grain 

 obviously contains more substance 

 for the development of the young 

 plant. Especially does this hold 

 good of the seeds of most legu- 

 minous and cruciferous plants, 

 such as peas, clover, turnips and 

 cabbage. The good samples, 

 however, cannot be separated from 

 the bad, by plumpness of form in 

 the case of seeds or fruits enclosed 

 in hard coats, such as buckwheat, 

 sainfoin and nuts of all kinds, for 

 the husk or covering is often normally developed in samples with 

 shrivelled and imperfectly-formed contents. 



{b) Colour. — All seeds of plants in a young condition are of 

 a pale greenish tint, but as they ripen some other well-marked 

 and characteristic colour is gradually produced. In mature 

 samples all the seeds are usually of uniform colour. In some, 

 however, this is not the case, seeds of various tints being met 

 with even when they are the produce of the same species of 

 plant and all equally well ripened. Red clover is an example, 

 and in the same pod of peas seeds of two colours are sometimes 

 present. The question whether in these and similar cases the 

 variations in colour are correlated with differences in germinating 

 capacity has not been satisfactorily investigated. 



All well-matured and healthy seeds, however, exhibit a colour 

 which can be considered as the normal one, and commercial 

 samples showing any deviation from this should be regarded 

 with suspicion. 



