138 Agricultural Section [pt ii 



The seeds of Hard Fescue and various Poas are generally present. 

 One worthless grass seed (Aira ccespitosa) is an almost constant 

 impurity owing to the fact that these two plants thrive under 

 similar conditions of soil, etc. and the seeds are harvested together. 

 Other impurities are Rumex acetosa, R. acetosella, Holcus lanatus, 

 H. mollis, Ranunculus repens, Alopecurus agrestis, etc. (see Figs. 

 40, 48, 114, and 152-155, and Chap. vn). 



Modern cleaning machinery, however, can by successive opera- 

 tions remove all or nearly all these impurities. Properly cleaned 

 samples should not contain more than five to ten per cent, of 

 chaff, and less than one per cent, of Tufted Hair-grass, etc. 



The Germination should reach 60 per cent, in seven days and 

 75 to 85 per cent, in eighteen days. Samples giving a germination 

 of over 90 per cent, are now sometimes met with. 



Anthoxanthum odoratum, L. 



For Botanical description see p. 61. 



Sweet-scented Vernal-grass is indigenous to the temperate 

 parts of Europe and Asia, and has been introduced into North 

 America. It thrives on a great variety of soils and within wide 

 limits of altitude and appears to be little affected by extremes of 

 temperature, moisture or drought. Although it thrives best in 

 deep rich soils it nevertheless succeeds in growing on the poorer 

 and drier types of land where the better kinds of agricultural 

 grasses would fail. 



This plant was formerly much over-rated in value as a forage 

 grass. The presence in it of a substance known as coumarin gives 

 the plant a characteristic fragrant smell especially when made 

 into hay. Chiefly for this reason it was supposed to be a valuable 

 constituent of the meadow. When masticated it is found to 

 possess a rather disagreeable bitter taste both in the fresh and 

 dried condition, and cattle are certainly not at all fond of it. Its 

 relative yield is also very small. Owing to these facts and the 

 high price of its seed it cannot be recommended for ordinary 

 farming purposes. Its most valuable characters are its extreme 

 hardiness, its earliness (flowering in April) and its undoubted 

 permanence. It is essentially a "bottom" grass and grows well 

 in shade. These points indicate that its main use lies, not as 



