IOO 



BOTANICAL GAZETTE 



I 



JARY 



occurs in Uruguay. He notes, however, that the culm habit in 

 Uruguayan oats and rye germinated at high temperatures is dis- 

 tinctly recumbent, whereas it is upright from the beginning in the 

 case of plants grown from seeds germinated at low temperatures. 

 The low temperature plants begin the formation of the culm (shoot- 

 ing) much earlier than do the high temperature plants. A typical 

 experiment with oats is outlined as follows: 



Date of seeding 



January 18 



Temperature during 

 germination 



January 18-23, 6-9 ; 

 January 23-25, 25 

 January 18 January 18-20, 25 ; 



January 20-25, 6-9 



Date of transfer 

 into field 



Beginning shooting 



January 25 March 15 



January 23 No shoot formation on 



April 25, shooting not 

 expected before 

 October 



In another series it was found that even 24 hours of exposure 

 to a germination temperature of 25 led to the same abnormal 

 course of development as indicated in the second series here quoted. 



Gassner and Grimme (4) have made one attempt to correlate 

 the effects of germination temperatures and the resistance of cereals 

 to frost injury. They analyzed the first leaves of winter and spring 

 rye germinated at 5 -6° 

 lings germinated at the 



C. and at 28 . They found that the seed- 



high 



high 



same 



Their 



results with rye are shown in table I. 

 Hutcheson and Quantz (7) condi 



growth 



wheat, oats, barley, and rye. All four crops were grown under four 

 temperature conditions, namely, i44°C, 16. 6° C, i8.3°C, and 

 23. 9 C. The higher temperature range had a distinctly detri- 



men 



grow 



course of development at all the temperatures used, although the 

 oat culms were weaker at the higher temperatures. The high 



