632 FARM ' SEEDS ' : GENERAL 



method of comparing the values of samples for purposes of pro- 

 ducing vigorous and healthy crops, provided, of course, that the 

 germination capacity is known. 



This test can be employed with advantage in the examination 

 of all kinds- of true seeds as peas, turnip, and clover, but its 

 special use is, perhaps, best seen and appreciated when applied 

 to fruits, that is to seed vessels with their contents, such as sain- 

 foin in the husk, and for the ' seeds ' of grasses. The ordinary 

 methods of examination as to brightness and colour, give little 

 or no indication of the value of the sample in the latter cases, 

 as the husks and chaff may be present and well developed, and 

 yet the seeds and fruits inside may be shrivelled and useless, 

 without giving any extemai indication of their condition. The 

 difference in weight, however, between chaff and husk with and 

 without their normal contents is very striking, and the presence 

 of ' deaf seeds in a sample at once reveals itself in the low 

 absolute weight obtained from it when compared with that from 

 a good one. 



It is obviously very inadvisable to purchase seeds of grasses 

 except by weight per bushel. Buying by volume or by bushel 

 without reference to weight is frequently done, but is not 

 prudent, as it may turn out that little else but chaff has been 

 bought in some instances. Ordinary commercial Rye-grass seed 

 for example varies in weight between 15 and 28 lbs. per bushel; 

 the first would contain a large proportion of chaff and im- 

 mature seeds, whilst the latter would consist mainly of good 

 seeds. No difference in external appearance might be notice- 

 able, but the weight of 1000 seeds from each would readily 

 reveal which is the better sample, and this test on account 

 of its importance and simplicity should never be omitted in 

 examination of all kinds of seeds. 



(c) Volume-Weiglit. — The volume-weight in the form of 

 weight per bushel has been employed from the earliest times 

 and is still almost universally adopted for the purpose of com- 



