FORM 635 



With wlieat, rye and barley, it generally does increase regularly 

 with an increase of size of the grain. Among oats, howevei, no 

 such proportion is met with ; it often goes up with a decrease in 

 their size ; but with some varieties it varies like wheat and barley. 

 With long kinds, the bushel-weight goes up with the size of the 

 grain, but among the more stumpy, short varieties of oats, this 

 relationship is frequently reversed. 



Medium-sized peas and beans, have usually a higher bushel- 

 weight than either large or small ones, and occasionally the 

 bushel-weight is the same even when the sizes are very different 

 from each other. 



Between the chemical constitution, shape, size, and other 

 peculiarities of seeds and their volume-weight, no fixed relation- 

 ship appears to hold, so that it is not of much service in deter- 

 mining quality of the seed for sowing purposes. 



6. Form, Colour, Brightness and Smell. — It is only by a care- 

 ful examination of seeds in regard to purity, germination capacity 

 and 'absolute weight,' that their real value can be accurately 

 determined, yet there are characteristics, such as shape, colour, 

 brightness and smell, which are very useful in helping us to 

 judge samples, and observations in reference to them should be 

 made. 



(a) Torm. — Seeds which are imperfectly ripened, or which 

 have suffered some check during their development, often show 

 evidence of the imperfection in their shape. They are shrivelled, 

 have more or less puckered coats, and differ in length, breadth 

 and thickness from those seeds which are well developed. Such 

 is seen in corn ripened too quickly by excessive dryness, and 

 where plants have been injured by being ' laid ' by the wind or 

 have suffered from the attacks of insects and parasitic fungi. 



Well-ripened seeds exhibit plumpness and rotundity of form, 

 and these features may be generally taken to indicate that the 

 embryo with its endosperm tightly fills up the entire space 

 enclosed by the seed coat. 



