Germination of Grass-Fruits. 215 



in the interest of greater accuracy and uniformity in recording 

 results of germination tests, to determine the possible influence 

 of any deviation in the germination from the normal upon the 

 practical valuation of the viability of seeds as established by the 

 germination test. 



Two kinds of abnormality occur at germination of grass 

 seeds on top of blotters : (a) the abnormal emergence of the 

 radicle, and (b) the stunting and dying off of the radicle within 

 the glumes. . Relative to the first abnormality the germination 

 test is usually carried for a sufficient length of time to allow the 

 abnormally emerging radicle to appear at the tip of the glumes, 

 and thus to become visible to the eye of the examiner. Such 

 seeds should be considered as viable and otherwise normal since 

 upon placing them in the soil they will grow normally. 



The stunting and dying off of the radicle within the glumes, 

 presents a more serious possibility of making errors in record- 

 ing results of germination tests. Reference to Table I reveals 

 that some of the grass seeds examined showed a rather high 

 percentage of mortality of their radicle ranging from 0.5% for 

 the Tall Oat grass to 28.3% for the Velvet grass. Now, the 

 Rules for Seed Testing as adopted by the Association of Official 

 Seed Analysts of North America at their meeting held in 191 7 

 at Detroit, provide that "seeds of Gramineae should not be con- 

 sidered as germinated unless both root and plumule elongate." 

 On the strength of this rule all the seeds referred to above having 

 developed a normal plumule but with no sign of a rootlet which 

 is dead within the glumes, would be regarded as not germinated, 

 which in certain cases would very appreciable misrepresent the 

 actual degree of viability. 



From Table 1 it will be seen that certain valuable grasses 

 showed a percentage of mortality of their seed-rootlets a good 

 deal higher than the margin of tolerance allowed in the seed 

 laws. It would be advisable to check up the results of germina- 

 tion tests of such grasses as Velvet grass, Meadow Foxtail, Ken- 

 tucky blue-grass and others, carried out on blotters, by subject- 

 ing the seed to a test in the soil. This would be especially ad- 

 visable in cases where an appreciable number of seeds germinat- 

 ing in a chamber on blotters show the plumule but fail to develop 

 the rootlet. 



