208 Maine Agricultural Experiment Station. 1920. 



not only causes the coleoptile to appear first but also prolongs 

 the distance covered by the radicle which first grows downwards 

 to bend upwards on striking the base of the lemma. However, 

 in several cases of abnormal germination the radicle was ob- 

 served to appear ahead of the coleoptile (Arrhenatherum, Alop- 

 ecurus, Dactylis, Lolium, Poa.) 



Within Type A two forms of abnormal germination may be 

 distinguished. 



i. The lemma is bent from the caryopsis by a larger or lesser 

 angle. The caryopsis is not raised in the glumes. 



The majority of the abnormally germinating fruits show 

 this type of germination. ( Lolium, Festuca, Poa, Cynosurus. 

 Agrostis). The angle at which the lemma is bent from the cary- 

 opsis varies generally from 45 ° to 90 . With Setaria germanica 

 and Phleum pratense this angle may reach almost 180 . The 

 radicle, emerging from the coleorhiza strikes upon the wall of 

 the lemma, curves upwards and growing along the inner wall of 

 the lemma appears at the tip of the latter. 



2. The lemma adheres to the caryopsis or is slightly bent 

 from it. The caryopsis, as a rule, is raised in the glumes. 



Alopecurus, Arrhenatherum, Holcus, Anthoxanthum, 

 Avena, etc. show this type of abnormal germination. The ex- 

 tending coleorhiza, on striking the base of the lemma, raises the 

 caryopsis a short distance. The protruding radicle pushes first 

 the caryopsis farther up, then bends upwards at a very sharp 

 angle to appear at the apex of the glumes. 



Anthoxanthum, Holcus and Alopecurus, which' are sur- 

 rounded also by the sterile glumes may exhibit a type of abnor- 

 mal germination illustrated in Fig. 40. The radicle breaks 

 through normally at the base of the lemma (Fig. 40B) and 

 striking upon the base of the sterile glume, turns upwards and 

 appears between the tips of the sterile glumes. 



Type B. The radicle does not appear at the apex of the 

 glumes but directing its point against the base of the lemma it 

 pushes the caryopsis out of the glumes and away for some dis- 

 tance. Figs. 39 and 44 illustrate this type of abnormal germi- 

 nation. With fruits enclosed also by the sterile glumes the 

 radicle may push out the caryopsis alone (Fig. 39) or it may 

 break through in the normal way at the base of the lemma and 



