SELECTION OF SEED. 105 



is a good plan to take a piece of white paper, moisten the 

 surface, and then lay the seed thinly over it, and carefully 

 examine the sample with a low-power magnifying-glass. 

 Any colouring matter that has been used may then gene- 

 rally be discovered, and the seeds of other plants mixed with 

 it be readily identified. Charlock seed, which is frequently 

 met with, has a rounder and somewhat larger shape; the 

 dock seed is much flatter; and the seeds of the common 

 heal-all Prunella vulyaris which abounds in some 

 districts in the clover fields, and flowers about the same 

 time, although of the 'same colour as the clover, are much 

 smaller in size, and may easily be distinguished from it. 

 In some of the foreign samples a large proportion of 

 pale-coloured seeds are met with. This probably arises 

 from their having been harvested before perfectly matured. 

 Clover seed contains a considerable percentage of oil in 

 its composition, and will germinate after being kept for 

 several years; it is, however, desirable in all cases, with 

 clovers as with other seeds, to obtain them as fresh as 

 possible. The ryegrass, whether Italian or perennial, is 

 equally subject to adulteration ; this, however, we shall 

 have another opportunity of speaking about. 



In sowing clover seed alone, the common seed-barrow 

 should always be made use of, as it is quite impossible to 

 distribute by broadcasting the small quantity of seed used 

 equally over the surface; when mixed with ryegrass the 

 different size and the different specific gravities of the seeds 

 render the task equally impossible. This small seed-sow- 

 ing machine (of which a perspective view is given in the 

 accompanying woodcut) consists of a barrow frame, carry- 

 ing a light wooden box of a given length, traversed 

 throughout its length by a spindle, armed at certain 

 distances every 6 or 8 inches with a circular brush (d), 

 placed opposite to an aperture in the side of the box, 

 which is covered by a copper plate, perforated with one 



VOL. II. 40 



